The ServoCity 8mm Pitch Slip-Fit Idler Sprocket (6mm Bore, 8 Tooth) - 2 Pack is designed to add tension to an 8mm pitch chain within an assembly. It is compatible with a 6mm outer diameter standoff, spacer, or shaft, and can be used with the goBILDA® Arc Slot Tensioner for precise tension adjustments. The integrated shims allow for close placement against a bearing without causing binding. Constructed from acetal, this sprocket offers low friction and excellent wear resistance.