The fiberglass coupling is not big in size. So set screw mounting is more suitable for the compact size. Encoder couplings and flexible coupling are working with the use of encoder and all kinds of motors (servo motor, DC motor, AC motor, gear motors). ROUNDSS couplings are available with many types. Only only aluminum coupling, steel coupling, there is also plastic coupling, fiberglass coupling. The flexibility and hardness of these couplings are different. Please choose suitable couplings according to your own application.