The 5.0mm socket is the best tool for tightening/loosening M2.5 nuts from off-road shock pistons. The 5.5mm socket is the best tool for tightening/loosening M3 nuts, such as those on the following: M3 nuts that secure off-road shocks to shock towers, M3 nuts that connect camber linkages with C-hubs and uprights, rear arm with upright, and steering linkages with Ackermann plate. Also used for mounting a touring car bodyshell rear wing. & The 5.0mm socket is the best tool for tightening/loosening M2.5 nuts from off-road shock pistons. The 5.5mm socket is the best tool for tightening/loosening M3 nuts, such as those on the following: M3 nuts that secure off-road shocks to shock towers, M3 nuts that connect camber linkages with C-hubs and uprights, rear arm with upright, and steering linkages with Ackermann plate. Also used for mounting a touring car bodyshell rear wing.