WIDELY USE:Used in of motor, metal and wood cutting lathes, electric fan, paper making, fiber manufacturing, washing machines and automotive manufacturing etc.It is not support for sawmill or lawn mower. REFLECTIVE TAPE:Reflective tape must be attached to measure RPM.Note: If measuring laser objects be sure to stick reflective paper. ACCURATE MEASUREMENT:Wide measuring range(2.5RPM to 99999 RPM);High resolution(0.1RPM or 1RPM).Accurately measure the speed of motors and machine parts.Measuring distance: (50- 500mm). TECHNOLOGY & DISPLAY: The use of microcomputer technology, anti-jamming technology and other advanced technology, can accurately measure the speed value. Large screen liquid crystal display, clear reading. PORTABLE:Compact and .Easy to take out . Dimension: . 131 (L) x 70 (W) x 29 (D) mm/ 5.16 x 2.76 x 1.14inches. With Reflective Tape Reflective tape must be attached to measure RPM. Material: Plastic Color: As shown Package Contents: 1 x RPM Tach 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.