"Measure ballistics on your sporter rifle or long-barrel handgun with the MagnetoSpeed Sporter Chronograph. The bayonet-style chronograph sensor attaches to any barrel between .5"" and 1"" in diameter with a strap, metal buckle, and triad thumb nut, and accommodates rifles with a muzzle brake or flash hider up to 2.7"" long. Simple one-button display easily cycles between recent shot velocity and statistics. 3 sensitivity settings allow you to fine-tune the chronograph for more accurate readings. Includes display unit, bayonet sensor, thick and thin rubber V-block spacers, and attachment strap.Manufacturer model #: MS_SP. Bayonet-style chronograph sensor Attaches to any barrel between .5"" and 1"" in diameter Accommodates rifles with a muzzle brake or flash hider up to 2.7"" long Simple one-button display 3 sensitivity settings"