Technical parameters: Measuring range: contact type 2 - 19999, non-contact type 2 - 99999 Counting measurement range: 1-99999 0.02% accuracy Resolution: 0.1 or 1 Measuring distance: 50mm-600mm Sampling time: 0.5 seconds (above 120 revolutions) 5-digit LCD display Measurement type: RPM, rotation speed, Hz, surface speed (m/min, in/min, ft/min, yard/min) and length (m, in, ft, yd) With laser aiming With backlight function Maximum, minimum, average and data retention 30 data storage: maximum, minimum and instantaneous values of 10 measurements Battery: 9V battery (not included) Operating temperature: 0℃ to 50℃ Storage temperature: -20℃ to 70℃ Colour:black Material:plastic Tips: The product may be updated constantly ,Due To Different Batches, The Actual Product May Have Slight Differences Or Color Differences, Which Does Not Affect Use Package Contents: 1 * tachometer 4 * connectors 1 * red protective cap 1 * English manual Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.