Specification: Outside Diameter: D19 L25 Outside Diameter: D=19mm Height: L=25mm Material: Aluminum Color: Silver The size you can choose: 3 x 8mm Character: The structure is simple, easy to install, buffer, damping, convenient to disconnect. The size is complete and the surface is smooth. Connect servo motor, stepper motor, encoder, screw driving, machine, etc. Notice: The size is refer to the hole,for example 6X8 is known as one head of the hole diameter is 6mm,the other is 8mm Package included: 1 x Coupler Package List 1The structure of this elastic coupling is uncomplicated, easy to install, and easy to disassemble. 2These couplings are suitable for connecting various shafts, including stepper motor outputs. 3Flexibility of coupling shaft removes stress between the motor and driving components. 4The flexible couplings are widely used in the coding of small CNC machine tools, simplifying the difficulty of debugging. 5This flexible coupling is made of aluminum, with smooth surface and long service life.