Weltool W4 PRO

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Weltool W4 PRO review

Weltool W4 PRO specifications

Brand/modelWeltool W4 PRO
LEPMirror style LEP flashlight
Max. Lumens568 lm
Max. Beam intensity / distance2,882,000 cd
Battery config.1*21700
Onboard chargingN/A
Review dateMay 2022


Weltool kind of started the whole craze around LEP flashlights back in 2018 with the Weltool W3. It was one of the greatest steps forward in the world of flashlights regarding beam distance and beam intensity.

Instead of using an LED as its light source, an LEP uses a laser as its light source. A blue laser projects its light onto phosphor to turn the blue laser into a white beam. Then, the beam gets focused using a convex lens. This type of flashlight can only used for long-distance objects. But I can already share a little secret: that won’t be for long because Weltool is working on a different type of application where the beam gets wider, more like the average LED beam.

But that review will come later.

So, how will the Weltool W4 PRO stack up against its older sibling, the W4? Will it throw farther? Did Weltool really improve the W4? On paper, it should, because the W4 had a claimed beam intensity of 1.7Mcd, and the W4 PRO 2.8Mcd… that’s a million candela more.

So, let’s find out.

Package quality.

When Weltool sent me the light, they were still working on the packaging, so I can’t show you any of that. They just shipped it in the W4 packaging. So, this is likely going to be inside the packaging…

  • The flashlight: Weltool W4 PRO
  • Weltool 21700 battery with USB-C port
  • USB-C charging cable for the battery
  • Pocket clip attached
  • Spare o-ring
  • Manual

Flashlight in use

The original W4 has been around since 2020, so a successor was due. And I’m glad they stuck with the W4 design because it looks and feels awesome.

The battery tube has the typical spiral knurling, which is also seen on the W3 PRO and W4. However, the neck of the light, as well as the tailcap, has no knurling. The tailcap has some cut-outs that work as an anti-roll feature, but only on a flat surface. It’s too little to protect from rolling off a slightly inclined surface. The pocket clip would help more in that regard.

Talking about the pocket clip.

The clip came pre-attached and is removable. But since it’s such a large light, I’m not sure how many people would use it though. A holster would probably be a better idea, which wasn’t included in the box. Weltool sells a holster for the W4 PRO separately, as: Weltool FH6. It’s only $9 and probably worth the little extra if you like using holsters.

There’s only one switch on the W4 Pro: a forward clicky tail switch. And because of that, you can momentarily turn the light on by half-pressing (not fully clicking) the switch.

It has a clear, clicky sound and can be pushed from about 45 degrees. The rubber boot feels a bit ’empty’ though, like there is a lot of play without touching the actual switch.

These flashlights have a particular use case since their beam is so tight and reaches so far. Think about search and rescue, signaling over long distances, or simply using it as a beacon.

Build Quality, and Warranty

The build quality of all Weltool flashlights is top-notch.

While some manufacturers mainly focus on output, Weltool pays great attention to build-quality. Just like the W4, the W4 Pro looks beautiful.

The body tube has particular Weltool knurling, with bare threads on 1 side and anodized threads on the other. The bare threads are towards the head and are protected from water ingress by a single o-ring.

The rear threads are lubed, screwed smoothly, and protected by 2 o-rings for waterproofness.

Weltool Warranty: from their website:

“Weltool warrants its products to be free of defects for a lifetime of use. We will repair any light device which is found to be defective under normal use.

​ From the date of sale (the serial number on the Lights body can show the date), the limited warranty for LED products is 5 years, and the warranty for LEP products is 2 years.

The above free warranty does not cover any damages or failure caused by:

  • Problems caused by alteration, misuse, abuse, or unreasonable
  • Battery leakage , improper operation or using poor quality battery
  • The products do not purchase from Weltool directly or its authorized dealers or other illegal way
  • Broken lens caused by external force
  • Lamp, switch runs out of its lifespan
  • rubber cap, O ring’s naturally aging
  • normal wear and tea, imprinting, or color finishes
  • Other problems caused by improper operation
  • Discontinued products

LEP, Lens, Bezel, Beam, and Reflector

The W4PRO is an LEP flashlight, not an LED flashlight, so the light source is based on a laser rather than an LED emitter. These types of lights have a higher beam intensity compared to LED flashlights.

The bezel is made of stainless steel, which increases impact resistance, and according to the manual, the W4 PRO uses a tempered glass lens for extra protection.

The laser warning, that was present on the older W4, is absent on the W4 PRO, and originally said: Warning, Class 3B Laser Product. btw Laser flashlights are never meant to be used by children because the beam is so intense, that it could hurt people’s eyes.

Talking about the beam, the W4 PRO uses the traditional mirror-type LEP module. This means that the beam can throw farther but is more prone to tint shifts. Those tint shifts are also visible in the beam.

Weltool W4 PRO Dimensions and size comparison

  • Length: 195 mm / 7.677 ”
  • Head diameter: 60.44  mm / 2.38 ”
  • Body diameter: 27 mm / 1.064 ”


  • Empty: 339.4 g / 11.97 oz
  • Including Weltool UB21-50 battery: 413 g / 13.28 oz

LEP Flashlight comparison

Size compared to other LEP flashlights

Image 1, Welltool flashlightsfrom left to right: Weltool W5, Weltool W4 PRO, Weltool W4, Weltool W3 PRO

Image 2,3: Acebeam W30, Weltool W4 PRO, Weltool W4, Jetbeam M1X WP-RX, Astrolux WP2, Jetbeam RRT M1X Raptor, Astrolux WP3, Nextorch T20L, Maxtoch L2K, Lumintop Thor 3.

Driver & User Interface:

Weltool uses its own driver and design. The firmware on the W4 PRO is very easy to use.

Available modes:

  • Low, High
  • Strobe

From OFF:

  • Half-press: momentary on
  • Single-click: Next mode memory (turned off in Low, next time will be High.. Turned off in High, next time will be low)
  • 3+presses: strobe

From ON:

  • Single-click: turns off


  • Strobe: 3 taps from off
  • Low: single click
  • High: just double-tap from off, and fully click the switch at the second tap.

Mode memory:

  • It doesn’t seem to work on mine. It has Next Mode Memory… which is quite horrible.

Blinky modes menu:

  • There is a hidden strobe mode. Access by half-pressing the switch 3 times when off. It looks more like a quick breathing pattern than a real on/off blinking.

Low battery warning:

  • Not that I could detect.

Lock-out mode:

  • No, it’s a mechanical switch, so a full click will turn it off.


  • No, not visible by eye.

Firmware / UI Conclusion:

Using next-mode-memory is a little mystery to me. I talked to Weltool, and maybe the next batch will always start from Low.

Batteries & Charging

I used a flat-top, non-protected 21700 battery for testing, which works fine. Both ends use a spring, giving you extra room to use different lengths of batteries. Weltool will include a Weltool UB21-50 battery with their W4 PRO. That is a 21700-type battery with a 5,000 mAh capacity and USB-C charging port. The charging cable is likely to be included as well.

Mine didn’t include a battery, so I took the following section from the older W4 review:

The specs on the battery say 5V 2.0A, and I could only get up to 1.5A. I upgraded my USB charger to read higher numbers, but I couldn’t get past 1.5A on this battery. So I would say it charges at max 1.5A. This means that charging takes about 3+hours.

During the charge, a little indicator LED is visible inside the positive side of the battery. There is a tiny hole with the indicator LED behind it. During the charge, it lights up red, and when finished, it turns blue.

Performance test

Lumen measurements:

All output numbers are relative to my homemade Integrating Sphere. It is set up with an Extech SDL400 Lux Meter for measurements, including a Kenko PRO1D ND-16 filter. The base measurement is done with a Convoy S2+ that has been tested at 255 lumens.

All of my readings were taken from a fully-charged brand new Samsung 40T, and a used Weltool UB21-50. The numbers of the 40T were slightly higher, so here you go; with Samsung 40T

ModeSpecsAt turn on30 seconds
High568 lm576 lm553 lm

Weltool asked us to do the lumen testing, and initially the numbers were about 3% higher. After testing I found out that the battery of the calibration light was low. I replaced the battery and tested it again.

Here are the numbers with the Weltool 21700 battery.

ModeSpecsAt turn on30 seconds10 minutes
Low210193197 lm178
High568 lm567550 lm514

Parasitic drain:

  • Couldn’t measure


The runtime test was done with the 50cm integrating sphere, including the Kenko Pro1D ND-16 filter and Extech SDL400 data logging Lux Meter.

According to the ANSI FL1 standards, the end of a runtime is when the output drops to 10% of the initial measurement (30 seconds after turn on).

ModeSpecifiedMeasured runtime
Low4h 30min4h 21min
High1h1h 7min

You can see a little strange behavior towards the end of the runtime in High mode. It’s also interesting to see that there is not so much difference between the 2 21700 batteries. the 5,000mAh battery runs a bit longer.

Throw Measurement

Measurements were done at 4 different distances, 5 meters, 10 meters, 20 meters and 40 meters. The numbers below are from the 20 meters measurements.

ModeSpecificationsCandela measuredMetersYardsMiles
High2,882,000 cd2,808,000 cd3351 meters3665 yards2.08 miles
Low1,108,000 cd1,088,000 cd2086 meters2281 yards1.30 miles

This means it does more than 2 miles.

Below is a comparison to other single-cell LEP flashlights. You can see how well it performs.. just crazy!

Candela comparison: best single-cell large head LEP flashlights

A list of the best single-cell LEP flashlights with large heads we reviewed: These numbers are NOT from the specifications but are measured by our reviewers. They include all single-cell LEP flashlights with large heard (+-60mm and above). The numbers include the measurement in lumens (lm), measure candela (cd), and calculated distance in meters, and yards. These numbers are all measured 30 seconds after turning on.

Flashlight (click for review)@30sec (lm)Candela (cd)MetersYards
Acebeam W304981,312,00022912505
Acebeam W357331,892,00027513009
Amutorch BT603161,644,00025642804
Astrolux WP23031,248,00022342443
Astrolux WP34452,412,00031063397
FireFlyLite LEP01391816,00018071976
Jetbeam M1X WP-RX4912,280,00030203302
Lumintop Thor 33111,728,00026292875
Maxtoch L2KS4422,308,00030383323
Nextorch T20L9751,284,00022662478
NlightD L15131,940,00027863046
Weltool W44502,184,00029563232
Weltool W4 PRO5502,808,00033513665

And below is an interactive throw comparison graph (candela), between the best single-cell LEP flashlights with large heads. Hover your mouse over the interactive graph below to see the details of each specific light.

(tip: hold your mobile phone horizontally to see the full graph). Or visit the full interactive graph here.

The next graph shows the same graph, but then focusing on the first 60 minutes of their runtimes. Or view the full 60min interactive graph here.


For the following beamshots, I used a Canon EOS 5D Mk2 and a 100mm lens. manual settings: ISO1600, .5sec , F4, 5000K

The tower is about 450 meters / 492 yards away.

Disclaimer: This flashlight was sent to me for review at no cost by Weltool. I have not been paid to review, nor have I been holding back on problems or defects.

Final Verdict


  1. Amazing throw: 3,350 meters of throw (2.08 miles)
  2. Nice design
  3. Great build quality
  4. Includes a 21700 battery with built-in charging


  1. Next-mode-memory
  2. Mirror type LEP beams have more color shift than the shine through models

Explanation on star ratings:

1: Avoid: my phone flashlight would be a better choice – 2: Poor: significant defect or issues; almost unusable – 3: Average: some defects or issues; but still usable 4: Good: recommended (minor issues) – 5: Great: highly recommended

Reviewer Marco
Author: Marco

4.0 stars: ★★★★

If it wasn’t for the next-mode-memory, I would have easily given it 5 stars.. But since it’s only 2 modes, you can easily switch between them, so it’s not as bad as having 5 modes with strobe and SOS and next-mode-memory. Weltool can likely change this in future batches.

On the contrary.. the WP4 PRO takes the LEP flashlight to the next level. Weltool did a great job, improving the already very impressive W4, by increasing the intensity by another 1 million candelas. Taking my hat off… bravo… Well done Weltool….

Weltool W4 PRO for sale

1lumen selects and reviews products personally. We may earn affiliate commissions through our links, which help support our testing.