Single 18650 flashlights
There are tons of 18650 on the market, from extremely cheap to very expensive. In the cheaper range don`t miss out on the Convoy flashlights, while my own favorite brand used to be Sunwayman.
One of the most beautifully machined flashlights out there. Supersmooth.
Multi 18650 flashlights
A few years back it all started with the famous SkyRay King. It was a budget multi-cell multi-led flashlight. It soon become a copy of a copy. Even these days you can see them for about $20-$40 each. Below are some other multi 18650 flashlights.
Sunwayman T40CS (2x18650)
Sigartype flashlight with MT-G2 led with 1500 lumens.
Acebeam K40M MT-G2 (3x18650)
A flashlight that has some very nice features, but is mainly used with operating with both hands.
BLF GT (Giga Thrower) Lumintop
Review of the farthest throwing LED flashlight of 2018. Monster search light. Works on 4 or 8*18650 cells.