This is a pack of two VRP 12mm "X V2" Flat Shock Pistons, intended for use with Team Associated 1/10 Scale Off-Road Vehicles equipped with V2 shock shafts (where the piston is attached to the shock shaft with a screw; not an e-clip). "X" pistons are designed to increase the rebound of the shock, without any compression changes, to keep your tires on the surface and in traction. Part# VRP2H1.6V2