Features: Brand new and high quality This Oldham coupling made of brass, which reduces friction and has sufficient strength.CNC-machining control 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. Compacts size, low moment ofinertia.Adapt to large radial- misalignment. It has high torsional stiffness.Greatly improve the accuracy, save time and convenient for operation. Specifications: Material:Brass Type:1Pc/2Pcs Size:Approx.23.8x15x13.6mm/0.93x0.59x0.53inches Package Includes: 2 Package Optional: Package 1 Include:1x Oldham Coupling Package 2 Include:2x Oldham Coupling note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item.