Features ADVANCED TECHNOLOGY --- Tachometer adopts microcomputer (CPU) technology, photoelectric technology, anti interference technology, and junction laser technology, which can test non contact measuring speed (RPM) or contact measuring speed (RPM), surface speed MULTI FUNCTIONAL --- Contact accessories and optoelectronic accessories can be switched at any time, achieving one machine with multiple functions. A speed sensor with grooves can conveniently measure the speed or length of wires, cables, and ropes. DATA STORAGE --- Automatically saves the maximum, minimum, and last values, and can store 96 consecutive sets of data. (After refreshing the measurement data, the tachometer starts to store data.) EASY TO USE --- Wide measurement range and high resolution. The large screen LCD display provides clear readings. The white backlit ensures reading in any light environment. Low battery voltage indication function. FINE WORKMANSHIP --- Smoothly shell design, comfortable to grip and use. The instrument is exquisite and sturdy, featuring strong and durable components and a sturdy and lightweight ABS plastic casing. Specification: Item Type: Digital Tachometer Mode: DT2236E Material: ABS Battery: 1.5V AA battery x 3 (without battery) Basic Parameters: Test Scope: 2.5 to 99999 RPM (r/min) non contact speed 0.5 to 19999 RPM (r/min) contact speed 0.05 to 1999.9m/min (m/min) contact surface speed Package List:1 x Meter 4 x Accessory1 x Manual  3 x Reflective Strip 1 x Storage Box  Package List 1 x Meter 4 x Accessory 1 x Manual 3 x Reflective Strip 1 x Storage Box