The MagnetoSpeed Sporter chronograph kit was designed to be used on barrels from .5" up to an 1" in diameter. It can also accommodate muzzle brakes, flash hiders, etc. up to 2.7 inches in length. Ideal for contoured rifle barrels (sporter barrels) and long-barreled revolvers. The MagnetoSpeed chronographs use ground breaking electromagnetic sensors, instead of problematic optical sensors, to eliminate common chronograph problems. They are easy to setup, impervious to light conditions, do not blow over from wind and can fit into your range bag. The MagnetoSpeed Sporter is the hassle free way to measure the velocity of your next hunting or target round. The MagnetoSpeed Sporter can record 99 consecutive shots before it resets to 0. There is no separation into strings or archive feature. Kit IncludesDisplay unitBayonet-style sensorThick and thin V-block spacersHeavy duty strap with thumb nut tightenerUltra-compact storage container2-year manufacturer warrantyFeaturesSimple, ...