protected 3.7V Li-Ion battery PCB - Soshine 18650 3400mAh 3.6V
which was attached unlike other protected battery at the positive terminal equipped with PCB Protection for short circuit, overload and over-discharge protection. Thus, the diameter variations that are caused by a connection of the electronics to the positive terminal have been fixed. By the always constant diameter it is suitable for just about all flashlights which may be equipped with 18650 Li-ion batteries. the Soshine recommended 18,650 batteries in particular for flashlights, LEDs, mech. Battery carrier, etc.