The Mantis X2 is the most powerful training aid for dry fire only practice. 
The X2 mounts to standard universal accessory rails.
The X2 is part of the second generation of Mantis Shooting Performance Systems. The key features of the second generation hardware include:
40% smaller
50% lighter
3x the battery life
4x the data rate 
Quick detach system
Collecting thousands of data points per second, the X2 analyzes your shooting in real-time.  For both pistols and rifles, the X2 works with dry fire on your actual firearm.
Ships with:
Mantis X2 sensor
USB charging cable
Mantis X2 Case + Foam Insert
Quick Start insert