These shafts can be used for a variety of purposes, including output shafts for gearboxes for axles for wheels. The set consists of four types of shafts (2 pieces each), as well as crank arms, nuts, grub screws, and a hex wrench. Set Contents: 3x150mm Hex Shaft (2pcs.), 3x100mm Hex Shaft (2pcs.), 3x100mm Threaded Shaft (2pcs.), and 3x100mm Round Shaft (2pcs.).