Stellar Instruments Stellar Contact and Non-Contact Digital Tachometer, SI510, 3 x 1.5V AAA Alkaline Battery The Digital Tachometer SI510 is a versatile and precise instrument designed for measuring rotational speed, surface speed, and frequency in a wide range of applications. This tachometer is ideal for... Quick view Qty in Cart: 0 Price: Log in for pricing and quote Subtotal: