An inaccurate tachometer can waste performance, fuel and engine life. Mechanical tachometers are notoriously inaccurate and should be checked at each annual and 100 hour inspection or any time aircraft performance is in question. The TruTach II Optical Digital Tachometer measures the true speed of your propeller from inside or outside the aircraft. Just point it at the propeller or rotor blades and TruTach II will directly display the rotational speed with a resolution of 1 RPM. No connection to aircraft systems is required and measurements may be made at any speed setting from 240 to 70000 RPM. 

Direct display is available for 2, 3, 4, and 5 blade propellers. Digital Signall Processing assures rock-solid display in single and multi-engine aircraft as well as helicopters. The compact 4-inch instrument weighs just 4 ounces and may be used with fast turning ultra-lights and kit plane propellers. Just turn it on, select the number of propeller blades and point. Automatic shut-off turns the unit off if you forget. The Tru Tach II includes a standard 9 volt battery providing 150 hours of operation.