Specification Brand : HAHIYO BulletPoint1 : Shock absorbsion:They are designed like a tightly wound corkscrew.Fit well between lead screws and motor shafts.They provide shock absorbsion to the Z-axis making smoother transitions.By using these you can soften the jerk mechanism result from the motors moving.After you place it on,there will be space between the two shafts internally.That allows the flexible center to float freely. BulletPoint2 : Four set screws lock:Accurately machined smooth set screws.The coupling that come with the original could pop out of position if pressure was applied to the Z gantry and often require realignment.With four set screws lock so easy to use,you can easily secure the coupler in the position you want,getting the shafts centered properly and securely in the coupler. BulletPoint3 : Solid durable alloy:Made with high quality aluminum alloy,gives it corrosion resistance,enhanced flexibility.After driver upgraded,a millimeter-level mistake could caused a disaster.The more solid couplers are harder to align and usually have a bit lower overall quality of print.You can't go wrong with a flexiable coupling in that case.Flexes well and returns to original shape without a problem. BulletPoint4 : A breeze to put on:They fit well and are easy to install.The buil-in set screws will save you from the trouble of bore extra holes and be more secure as well.This will got your printer back up and running.Working great,without bringing backlash or wobble.All you need to do is just to take the motors off and replace the old couplers on the Z-axis,the whole processes could be done in minutes. BulletPoint5 : Multi-Function:These are nicely built shaft coupling for your project.If your 3D printer printing more and more unlevel,it’s time for you to use these and solve the problem.Great for a kit-built CNC router and robot projects,too.Or you can use it for DIY auto fish feeder.More over,try to use them between a servo motors and an encoder.The improvement in quality is noticeable for difference purpose. Color : One Color ExteriorFinish : Aluminum ExternallyAssignedProductIdentifier : 7310399081836 ExternallyAssignedProductIdentifier1 : 0791809147576 ExternallyAssignedProductIdentifier2 : 791809147576 IncludedComponents : No ItemName : Hahiyo 8mm to 6.3mm Inner Diameter Shaft Couplings Flexible Shock Absorbsion Stretchable Coupler Set Screws Lock Aluminum Alloy 1 Piece Easy Install Multi-Function for 3D Printer Stepper Motor Z-axis ItemPackageDimensions_Height : 13.3 centimeters ItemPackageDimensions_Length : 1.2 centimeters ItemPackageDimensions_Width : 8.6 centimeters ItemPackageQuantity : 1 ItemTypeKeyword : 3d-printer-accessories Manufacturer : HAHIYO Material : Aluminum MetalType : Aluminum ModelName : ESXSWYDR ModelNumber : 2021012004-3D Couplings NumberOfItems : 1 PartNumber : 2021012004-3D Couplings ProductDescription : Material:High quality aluminum alloy Size:Inner diameter 8mm to 6.3mm Package Include: 1 piece shaft coupler These are nicely built shaft coupling for your project.The improvement in quality is noticeable after replaced. ProductSiteLaunchDate : 2021-01-20T12:25:03.416Z Size : 4.5NM Style : 8*6.3mm-1Pcs SupplierDeclaredDgHzRegulation : not_applicable UnitCount : 1