Note: The coupling is unmarried joint, and has keyway."10x20x45mm(keyway" ability its internal diameter is 10mm, outer diameter is 20mm and length is 45mm, with keyway.For quite a lot of general-purpose machinery occasionEach part of extreme rotation perspective of 30 °Material: 45# SteelSize"Inner Diameter(d) * Outer Diameter(D) * Length(L2):10x20x45mm(keyway),12x23x52mm(keyway),14x25x59mm(keyway),14x28x60mm(keyway),16x32x68mm(keyway),16x32x75mm(keyway),16x32x82mm(keyway),20x36x87mm(keyway),20x40x94mm(keyway),22x45x95mm(keyway)(if you would like different size, please ship us a message)Package Included:Universal Joint x 1