The 8mm REX™ Plastic Spacer (12mm REX™ OD, 12mm Length) - 12 Pack is engineered to fit onto an 8mm REX™ shaft, facilitating the precise alignment of drive components like gears and sprockets. It also serves to axially restrain components such as bearings, ensuring a well-spaced and robust assembly. Constructed from durable acetal plastic, this spacer is lightweight, enhancing the efficiency of mechanical builds.