Magnetospeed v3 chronograph barrel mount w/hardcase Features:-Three-button menu system-Battery options: (1) 9-Volt or (2) CR123s-Easy access battery compartment, no need for screwdriver to swap batteries-Improved shooting modes, with the ability to now operate with air guns-Downloadable firmware updates-Advanced data logging & troubleshooting capabilities-More compact & rugged display housing-Rapid mode with rate-of-fire-Redesigned bayonet-Rugged strapping system-Dual data connection pointsKit Includes:-Display unit-Retractable connection cable & Standard 6 ft. connection cable-Stainless steel blast shield-Thick & thin rubber V-block spacers-microSD card with adapter-Bayonet sensor-Polymer spacer kit with screw hardware & allen wrench-Heavy duty strap with thumb nut tightener-Hard case with custom cut foam-Alignment rod-Instructions Other Features: Mounts on b arrels.5"-2" dia.& muzzle devices up to 3.5" in length, micro sd card, blast shield, dual data ports, cables, advanced data logging, thick & thin v-block spacers, alignment rod, downloadable firmware updates, hard case, uses 1ea.9v or 2ea.Cr123