The Extech 461830-NIST is a digital StroboTach tachometer. Freeze motion and analyze rotating objects without contact. Checks and analyzes motion and speed by simply aiming and synchronizing its flash rate (FPM) with a rotating object. Ideal for measuring the speed of moving gears, fans, pumps, motors and other equipment used in general maintenance, production, quality control, or laboratories. Complete with 6 ft power cord, handle and can be tripod mounted. Includes certificate traceable to NIST.