Flexibility of coupling shaft gets rid of pressure between the motor and using components.The shaft couplers are widely applied to small CNC machines encoding and 3-D printers Z shaft coupling, simplifies the debugging difficulty.6mm to 8mm shaft usage diameter, 25mm length, 18mm diameter, set screw type, beam coupling.Zero backlash. One-piece metallic spring coupling. For little torque shaft connect.Absorption of parallel, angular misalignments and shaft end-play via spring action.Widely used in drive programs for encoders, instrumentation,lead screws, small pumps, feed rollers and anyplace gentle to medium duty, torsionally bendy coupling is required. Material: Aluminum alloyColor: SilverWeight: 14g Package Content: 1 * Shaft couplingOnly the above package content, other merchandise will not be included.Note: Light shooting and diversified displays could cause the color of the thing in the picture a little bit diverse from the genuine thing. The measurement allowed error is +/- 1-3cm.