The SDCF-XXX-A series is cup-shaped standard cylinder structure for the flexible wheel, which is small size. The input shaft is directly coupled with the inner hole of the wave generator through a flat key connection. It is usually fixed by a rigid wheel and used for the connection mode of the the flexible wheel’s output end. The spotlight is high meshing degree, light weight and compactness. The features cover high transmission accuracy, lower noise, fast response and good reliability.