This is a part manufactured by the ALPS Electric Co., Ltd. It is a rotary encoder, model RK09D1130-F30-C0-B104. This type of rotary encoder is designed as a precision, electromechanical device that senses the position of a shaft and outputs digital or analog signals. Its output type is digital and its resolution is specified at 30 pulses per revolution, with a max pulse frequency of 104 Hz. It has a 6mm diameter flatted shaft, a rated input of 5V, a dielectric strength of 200V AC for one minute, and an insulation resistance of 100M O Min. at 250V DC. Additionally, its size is 12.5 x 10.5 x 14mm and its mass is 8.5g.