These rugged tachometers are designed for heavy duty service and measure RPM, FPM or other production rates of speed. They are precision built instruments and each unit is individually calibrated with easy to read, hand drawn scales. These instruments feature noiseless operation. instantaneous pointer response and negligible torque. They are supplied in 3", 4", 5" and 6" sizes with ranges from 0 - 50 on up to 0 - 4,000. Connections can be made to the side, bottom, back or top of the instruments with connectors such as couplings, pulleys and timing belts.