Specification:Operating voltage: 3.0V/DCBattery: CR 2032 x2 220MAH lithium batteryMaximum current consumption : 6 mAMeasuring resolution: 0.1 degreesOperating temperature: 0 to 40 degrees CelsiusDimensions: 1108x53.7x16 mmWeight: 36 gHas angle reset and lock function.Detectable angle range is 90 degrees.With automatic screen reversal function (built-in three-axis gyroscope)< p>Applicable pallet width: 20 mm ~ 75 mmApplicable to 250 ~ 800 mm main rotor, with or without ailerons.Built-in power saving function automatically turns off the power after 3 minutes of standby. (Automatic shutdown after 3 minutes of stopping)Instructions:1. The ON/OFF key is for turning the machine on/off.Two, hold the key, angle lock key3. ZERO key, place the instrument on a horizontal platform, lightly press the ZERO key, the value will return to zero, and the LCD will display 0.0. The angle value measured at this time is the relative horizontal angle value.1. It doesn't matter whether the plane the helicopter is placed on is absolutely horizontal or not, you need to find a relatively horizontal surface on the helicopter (usually the engine or exhaust pipe). At this time, the helicopter must be stopped!2. After finding the relative horizontal plane, press the ZERO key to clear it (use this plane as the horizontal plane to calculate the angle)3. Use a digital pitch ruler to measure the propeller angle, positive and negative angles, with an accuracy of 0.1 degrees, and supports reversing, which is extremely convenient!< p>4. If it is the same helicopter, it must be reset to zero when measuring on another platform or at the front of the helicopter, to prevent the platform from tilting forward, towards the back or to the left or right.