Specification Brand : HERCHR BulletPoint1 : [Wear Resistant Steel]: Universal joint coupling is made of No. 45 steel material, possess high strength, wear resistant, The universal joint coupling provides torque transmission and alignment, flexible and easy for use. BulletPoint2 : [Easy Install]: Rotatable universal joint shaft coupling is equipped with 1 wrench, 10 set screws, easy for you to install and replace, Rotatable universal joint shaft coupling is suitable for RC model car, model ship, etc, practical BulletPoint3 : [RC Coupler Connector]: Universal joint coupling is widely used in shaft connection. The rotable coupling is perfectly applicable for RC model car and RC model boat,is perfect motor shaft fitting accessories. BulletPoint4 : SIZE PARAMETERS: Product length for 23mm, product diameter is 9mm, connecting hole diameter is 4mm, very accurate BulletPoint5 : [Universal Joint Shaft Coupling]: length 23mm, diameter 9mm, connecting hole diameter is 4mm, very accurate Color : #549 ItemName : 4mm Joint Shaft, 5 pcs Universal Joint Shaft Coupling 2-Stage Rotatable Steel DIY Motor Flexible Shaft Coupling Joint Connector for RC Car Boat ItemPackageDimensions_Height : 8 centimeters ItemPackageDimensions_Length : 13 centimeters ItemPackageDimensions_Width : 10 centimeters ItemPackageQuantity : 1 ItemTypeKeyword : pin-and-block-universal-joints Manufacturer : HERCHR Material : Metal ModelName : Hyuduokbua3rgxmv ModelNumber : Hyuduokbua3rgxmv PartNumber : HERCHR35e4kpgrcy ProductDescription : Specification: