Specification Brand : daier BulletPoint1 : Durable Material: The coupling connector is made of 45# steel( it is better than copper and aluminum alloys ), heat and electroplated process make it sturdiness and insulation, striking shaft more stable and easy for installment and replacement. BulletPoint2 : Widely use: Used in model shaft connection, perfect accessories for RC Model motor. BulletPoint3 : M8 Size: Cylinder diameter 12mm/0.47inch, cylinder height 10mm/0.39inch, out diameter:22mm/0.86inch, the overall height of 12mm/0.47inch. BulletPoint4 : A screw shaft can be fixed to the plane by rotation, through the control of the positive and negative rotation of the motor to achieve up and down drawing and other DIY functions. BulletPoint5 : Package included:4Pcs M8 Flange Shaft Coupling Color : Silver DriveSystem : External Hex ExteriorFinish : Aluminum ExternallyAssignedProductIdentifier1 : 0609411977613 ExternallyAssignedProductIdentifier2 : 609411977613 FinishType : Stainless Steel GradeRating : industrial ItemName : 4Pcs M8 Flange Coupling Connector, Threaded Shaft Gear Motor Flange Nut DIY Coupling Screw Guide Shaft Support for The Motor ItemPackageDimensions_Height : 8.9 centimeters ItemPackageDimensions_Length : 1.3 centimeters ItemPackageDimensions_Width : 8.2 centimeters ItemPackageQuantity : 8 ItemShape : Square ItemTypeKeyword : coupling-nuts Manufacturer : daier Material : steel MaximumShearStrength : 370-700 MPa MeasurementSystem : Metric MetalType : Alloy Steel MetalType1 : Carbon Steel MetalType2 : Alloy Steel ModelNumber : T742 NumberOfItems : 4 NumberOfPieces : 4 PartNumber : T742 ProductDescription : Flange Shaft Coupling, suitable for model shaft connection, perfect accessories for RC Model motor, etc A screw shaft can be fixed to the plane by rotation, through the control of the positive and negative rotation of the motor to achieve up and down drawing and other DIY functions.