The servo motor encoder is in modular design. There is no housing. It can be directly mounted into the back of the servo motor. 35mm OD size is smaller than common type of servo motor encoders. The function is the same and it is with low cost. In recent years, along with the popularization of automation, intelligence, miniaturization, modular type encoders have been welcomed more and more. The structure of modular type encoders is more compact compared with other encoder. It reduces production costs.