Specification Brand : Generic BulletPoint1 : Shaft coupling is made of brass,anti-corrosive and high precision fine workmanship,long service life. BulletPoint2 : Can be used in model airplane boat, robot,RC modelmotor etc. BulletPoint3 : Size:inner diameter:2mm to 5mm;outer diameter:9mm;Length:20mm BulletPoint4 : Flexibility of coupling shaft removes stress between the motor and driving components. BulletPoint5 : Easily installed where major disassembly would otherwise be required. Color : Brass ItemName : 1PCS Brass Shaft Coupling 2mm to 5mm Flexible Shaft Coupling Joint Connector 20mm Length 9mm Diameter with Screws and Wrench for RC Model Motor?Brass? ItemPackageDimensions_Height : 3 centimeters ItemPackageDimensions_Length : 17 centimeters ItemPackageDimensions_Width : 14 centimeters ItemTypeKeyword : multi-flex-couplings Manufacturer : Generic Material : Brass ModelNumber : ASDHJKUIO-285 NumberOfItems : 1 PartNumber : ASDHJKUIO-285 ProductDescription : Features: Shaft coupling is made of brass,anti-corrosive and high precision fine workmanship,long service life. Can be used in electric car toy, robot,RC modelmotor etc. Easily installed where major disassembly would otherwise be required. Flexibility of coupling shaft removes stress between the motor and driving components.