The MDR-04S with SMD10x10mm Rotary Encoders ROHS manufactured by SM Switch is a type of electronic component used to monitor the angular position of a shaft or axle. It is a non-contact electronic device which is designed to record rotational movements of a shaft and converts it into either an electronic signal or a digital count. It features an operating temperature range from -40 to +85 degrees Celsius, a resistance rating of 10KO, a maximum revolution speed of 15rpm, and a built-in switch. The encoder is constructed of long life thick film hybrid technology with a lifespan of up to 1 million cycles, and comes in a compact SMD (surface mount device) package that measures 10x10mm. It is compliant with the EU RoHS standard, and is designed for use in security systems, robotics, industrial automation, motor control, and other applications that require precise positioning control.