【LCD Display】:Built-in backlight ensures clear visibility in any environment. Memory Function: Automatically memorizes the maximum, minimum, and last measurement values ??during the measurement period. 【Dual-Function Device】:Supports contact/non-contact and linear velocity measurements, equipped with 3 different contact adapters to meet measurement needs in various situations. 【Measurement Range】:Photoelectric: 2.5~99,999 rpm, Contact: 0.5~19,999 rpm, Linear velocity: 0.05~1999.9 m/min / 0.2~6,560 ft/min. Measurement accuracy: ±(0.05%n+1d). Sampling time: 1.0 second (below 60 rpm). 【Material】:Lightweight yet robust ABS plastic housing with an ergonomic design for comfortable grip and easy use 【Applications】:Primarily used for measuring revolutions per minute (RPM), frequency, surfaces velocity, and length in equipment such as motors, fans, automobiles, and paper mills.