TruTach II Digital Propeller Tachometer

Accuracy and ease of use puts the TruTach II Propeller Tachometer at the top of the Reeves instrument list. The aircraft instrument operates optically, requiring no physical connection to the aircraft to display the rotaional speed of the prop. Operation? It's easy: Simply switch on, select the number of prop blades, and go. No calibration necessary.FeaturesOptical read accurate to +/- 1 RPMMeasures from 24 to 7 RPMReads single and multi-engine prop aircraft with 2, 3, 4, or 5 bladesTakes one 9-volt (approximately 1-hour life)On-screen low battery indicator3.8" x 2.4" x 1.5"4 oz