Features: brand new and high quality This Oldham coupling made of brass, which reduces friction and has sufficient strength.CNC-machining controls the clearance at the connection location. The use of this shaft coupling for the Z-axis screw of the 3D printer will reduce the printing quality problems caused by the swing of the hot bed during the printing process. Small in size and easy to install and disassemble Compact size, low moment of inertia.Adapt to large radial- misalignment It has high torsional stiffness Package Includes: 1 PC x Oldham Coupling Specifications: Item: Oldham Coupling for 3D Printer T8 Screw For Z Axis Material:Brass Size:approx 24x13.6x15mm/0.94x0.54x0.59in note: 1.Transition: 1cm=10mm=0.39inch 2.Please allow 0-1cm error due to manual measurement. pls make sure you do not mind before you bid. 3.Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you!