1. Mechanical principle: The planetary drive is adopted. The inner gearing reducer device is generated by the inner engagement of cycloid gear tooth and pin gear. And then the input rotational speed is reduced and output with an inverse coaxial direction. 2.Features: high speed ratio, smaller size due to the planetary drive, and no axial force. 3 .Types of installation and output: base type, flange type installation, and output through solid shaft. 4. Type of input: coupled-type motor, input through solid shaft or through flange. 5. Speed reducing ratio: 1-stage 9-87, 2-stage 99-5133.