Specification AgeRangeDescription : adult Brand : daier BulletPoint : Needle-Bearing BulletPoint1 : Size: Inner Diameter: 3mm to 3mm; Length: 13mm/0.51 inch; Outer Diameter: 7mm/0.28 inch; Color: Silver Tone. BulletPoint2 : Durable: Our universal joint is crafted from high-quality pure copper, ensuring durability and long-term use. BulletPoint3 : Versatile Application: This coupling universal joint is ideal for various applications, including servo motor systems, 3D printers, CNC machines, DIY encoders, and more. BulletPoint4 : Function: The purpose of our universal joint is to securely connect the driving shaft and the driven shaft, allowing them to rotate together and transmit motion and torque effectively. BulletPoint5 : Package include: includes 6Pcs 3mm to 3mm universal joints, 12Pcs M2 screws, and 1Pc M2 wrench. Color : S6305zz ExteriorFinish : Silver ExternallyAssignedProductIdentifier : 7329399486879 ExternallyAssignedProductIdentifier1 : 685144261021 ExternallyAssignedProductIdentifier2 : 0685144261021 ItemName : 6Pcs 3mm to 3mm Universal Joints, Rotatable Universal Steering Shaft U Joint Coupler for RC Boat Car ItemPackageDimensions_Height : 1 centimeters ItemPackageDimensions_Length : 8 centimeters ItemPackageDimensions_Width : 13 centimeters ItemPackageQuantity : 6 ItemTypeKeyword : pin-and-block-universal-joints Manufacturer : daier Material : Copper ModelName : CFVUTTWQ ModelNumber : 68514426102 NumberOfBoxes : 1 NumberOfItems : 6 PartNumber : TY139*6 ProductDescription : Application: Universal joint coupling adopts a special coupler, used for connecting the motor shaft and the hexagon wheel of the robot, and other DIY models. Ideal for rc model motor,widely used in model shaft connection.compatible with 1/24 1/18 RC car boat,DIY airplane ,model sailing boat,popular science model transmission,etc.