The XPPM is lithium battery power supply compatible with the X26P, providing power for approximately 500+ firings. The extension that provides a place to store an extra cartridge is compatible with the X26P and X1. Battery Features: Extension provides storage for extra cartridge for X26P & X1 Approximately 500+ firings Device Compatibility: X1 X26P TASER is a trademark of Axon Enterprise, Inc., registered in the U.S. and other countries.