Don't miss that once-in-a-lifetime shot on account of a dead battery. This CTA Digital battery replaces the Casio NP-20 digital camera battery. This battery was designed to meet or exceed OEM specifications and is 100-percent compatible to the original equipment chargers. Look to Overstock.com for everything you need to deck out your digital toys. Specifications: Chemistry: Lithium Ion Voltage: 3.7V mAh (capacity): 630mAh Run time (shooting time): up to 200 shots For use with the following digital cameras: Casio Exilim EX -M1/Exilim EX-M2/Exilim EX-S1/Exilim EX S1PM/Exilim EX-S2/Exilim EX S2PW/EX-S3/EX-Z3/EX-Z4U