This is an optional set of two Tekno RC EB410/ET410 CNC 13mm Shock Pistons, intended for use with ET410 Competition 1/10 electric 4WD truggy kits and the EB410 electric buggy kits. These pistons are machined from self lubricating Delrin material and improve the consistency and fine tuning of your vehicle. These are flat on both sides and drilled with eight 1.2 millimeter holes.