Features 1、LED Round Light Beam: It will indicate the approximate speed value, display items are optional. 2、Four Digital Tubes: It can display the relevant parameters separately, and the speed and frequency can be converted to each other. 3、Easy to Set: Relevant parameters can be set through the panel buttons and DIP switches. 4、Protection Functions: The engine digital tachometer with over speed and over frequency alarm protection functions. 5、High Quality Material: The engine digital tachometer is made of high quality ABS material, small in size, lightweight and portable. Specification Item Type: Tachometer Material: ABS Model: GT33 Purpose: Measurement of Engine Speed, Frequency, Accumulation Time Power Supply: DC 8-36V Power Consumption: Maximum 1.2W Input Speed Signal Range: Freq 200Hz~6.5KHz Range of Input Speed Signal Range: AC3~65V Speed Measurement Accuracy: Error ≤±1% (Within the Range) Input Power Generation Signal: AC 50~280V (45~70Hz) Frequency Measurement Accuracy: Error ±1% (Within Range) Alarm Output: Negative Output, Maximum DC1A Operating Temperature Range: -40℃ ~ 65℃ Package List 1 x Tachometer 1 x Manual