Overview: Trust Fire Lithium Batteries -Blue (2-Pack) Don't heat, incinerate or reverse polarity Environment friendly Specification: Trust Fire 18650 2500m Ah 3.7V The voltage of full charge & cut-off discharge is 4.2V & 2.75 V Dimension (CM):3.6 x 1.8 x 6.5 Weight (Kg):0.0858