The MagnetoSpeed V3 ballistic chronograph kit was designed to be used on barrels and suppressors from 1/2 inch all the way up to 2 inches in diameter. In addition to the larger diameter tolerance the V3 also has one inch more clearance in the blast zone to account for longer (up to 3 in most cases) muzzle brakes flash hiders etc. - MagnetoSpeed V3 features an improved designed with the following features: - Improved Display - Three-button menu system - Battery options are; (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 and troubleshooting capabilities - More compact and rugged display housing - Rapid mode with rate-of-fire - Redesigned Bayonet - Rugged strapping system; with metal buckle and triad thumb nut - Proven technology with updated sensor design - New profile and color scheme - New bracket to allow for future alternative attachment options - Dual data connection points - Kit includes: - Display Unit - Retractable connection cable - Standard 6ft connection cable - Stainless steel blast shield - Thick and thin rubber V-block spacers - microSD card with adapter - Bayonet sensor - Polymer spacer kit with screw hardware and allen wrench - Heavy duty strap with thumb nut tightener - Hard case with custom cut foam - Alignment rod - Instructions