Description: Flexible Shaft Coupling OD18mmx25mm CNC Stepper Motor Coupler Connector 6.35 To 8mm Specification: Material:Aluminum(LY12) Outside diameter:D=18mm Height:L=25mm Color:silver. The size you can choose: 8X8mm 6.35X8mm 6.35X6.35mm 6X8mm 6X6.35mm 6X6mm 5X8mm 5X6.35mm 5X6mm 5X5mm 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 8X10 is known as one head of the hole diameter is 8mm,the other is 10mm Package included: 1XCoupler