The MagnetoSpeed Sporter chronograph delivers precise shot velocity measurements for rifles and revolvers with 1/2 inch to 1 inch diameter barrels. Features a bayonet-style sensor that accommodates muzzle brakes and flash hiders up to 2.7 inches in length.MagnetoSpeed Sporter Chronograph KitCompatible with 1/2" to 1" diameter barrelsAccommodates muzzle devices up to 2.7" lengthSimple one-button display with shot statisticsThree sensitivity settings for fine-tuning9-volt battery included with easy-access compartmentQuick-attach strapping system with metal buckleComplete kit with display unit bayonet sensor spacers and storage containerIdeal for contoured rifle barrels (sporter barrels) and long-barreled revolvers this chronograph provides accurate velocity data for ammunition testing and load development.