... controller,high precision, low cost, very suit for all the customer RSA series achieve adjustment of angle automatively by stepping motor ... drive ,precision worm and worm wheel driver,precisional axis design,ensure high precision, high load .Stepping motor ... and motorized by hand,reloading actuator motor Specification ModelRSA60RSA100RSA200RSA400Rotation ratio90:1180:1720:1Relsolution ...