2 x 18650 Double Two Slot Battery Holder (output 7.4v)
Flashlight, Tactical Flashlight, 1000 High Lumens LED Flashlight, Bright Flashlight, Rechargeable Tactical Flashlight with 18650 Battery, Small Waterproof Tactical Flashlight for Camping, Emergency
The Ultimate Guide to the 18650 Battery - Fenix Lighting