Notice: The coupling is B Type Three-section Joint, and has keyway."16x30x105mm(keyway" skill its inner diameter is 16mm, outer diameter is 30mm and size is 105mm, with keyway."25-30x49x170(8)" potential its internal diameter is One finish 25mm and the alternative end 30mm, outer diameter is 49mm and length is 170mm, with 8mm keyway.For a variety of general-purpose equipment occasionEach section of utmost rotation perspective of 30°Material: 45# Carbon SteelSize"Inner Diameter(d) * Outer Diameter(D) * Length(L2):16x30x105mm(keyway), 18x32x115mm(keyway), 20x36x128mm(keyway), 22x38x145mm(keyway), 25x44x163mm(keyway), 25x49x170mm(keyway), 30x49x170mm(keyway)(if you wish different size, please ship us a message)Package Included:Universal Joint x 1