The ServoCity REX® 12mm Shaft w/ E-Clip (Stainless Steel, 168mm Length) is a robust component designed for heavy-duty applications within the goBILDA® build system. It features a 12mm diameter, allowing it to drive motion components like hubs and sprockets effectively. The shaft's design combines a round profile for smooth operation in conventional bearings, while the E-clip provides directional constraint. Additionally, the shaft includes M4 threaded holes at each end, enhancing its versatility for various mechanical configurations.