The Eddy-Current Type Analog Hand Tachometers are precise and capable of providing instantaneous measurement readings with steady pointer movement. As shown in the photograph, the range selection switch is conveniently located for thumb use, while the stop button has been positioned for finger operation. The outer scale provides rpm readings, while the inner scale measures directly in meters/minute or feet/ minute using optional accessory wheels. Each tachometer is supplied with a standard 6-in. (152-mm) circumference wheel; feet/minute measurements are obtained by dividing the outer scale reading by 2. Meter and foot wheels are optional accessories.