Sportsman Supply Inc. Shooting Chrony 7000136 Gamma Master Chronograph with Ballistic Chrony Printer, Silver Green Measures the speed of any projectile from 30 feet per second to 7000 feet per second. Includes everything from the Shooting Chrony Gamma Chrony plus more Powered by a single 9 volt battery. Made of 20 gauge steel but weighs less then 2 1/2 pounds Measures speed within .5-Percent accuracy.