The 8mm REX™ Plastic Spacer (12mm REX™ OD, 16mm Length) - 12 Pack is engineered to fit onto an 8mm REX™ shaft, facilitating the creation of space between mechanical components. This spacer ensures precise alignment of drive elements like gears and sprockets, while also providing axial restraint for components such as bearings, contributing to a robust and well-structured assembly.