This is an easy-to-use instrument to measure the rotational speed. It Features non-contact design, automatic measurement and digital screen, and can be widely used in electric motors, fans, washing machines, automobiles and more manufacturing industries. Pocket size and light weight for easy portability. Features: Portable handheld tachometer with 2.5-99999rpm testing range, 50-500mm effective testing distance. Non-contact design, automatic range, quick measurement, high precision. With memory function for convenient use. Digital LCD screen for easy reading, clear at a glance. Powered by 4 AA batteries (not included). Compact and lightweight, easy to carry with the cloth bag, convenient to use anytime anywhere. Widely used in electric motors, fans, paper making, plastics, chemical fiber, washing machines, automobiles, airplanes, ships and other manufacturing industries. Note: 1. For more details, please read the user manual. 2. Size and color may be slightly different because of manual measurement and different light conditions. Thanks for understanding. Specifications: Model: TA8146A/ TA8146C (Optional) Color: Black Material: ABS Test Range: A: 2.5-99999 r/min C: 2.5-99999 r/min (photoelectric rotation speed) 0.5-19999 r/min (contact rotation speed) 0.05-1999.9 m/min (contact surface speed) 0.16-6560.0 ft/min (contact surface speed) Accuracy: (0.05%+1 digit) Range Selection: Auto Switch Sampling Time: 0.8s (over 60 r/min) Effective Distance: 50-500mm Power Supply: 4 * AA Battery (NOT included) Tachometer Size: A: 160 * 76 * 40mm / 6.30 * 2.99 * 1.57in C: 205 * 76 * 40mm / 8.07 * 2.99 * 1.57in Package Size: 240 * 90 * 52mm / 9.45 * 3.54 * 2.05in Package Weight: A: 322g / 11.36oz C: 346g / 12.20oz Package List: 1 * Digital Tachometer 2 * Reflective Sticker 1 * Storage Bag 1 * User Manual (English)