PPC Double End Assembly 7pc Wrench SetPPC Double End Assembly 7 Piece Wrench Set Don't Mark up your fittings during assembly! Use the correct tools! These wrenches are designed to work on size 3 up to 20. These billet aluminum wrenches are . 390 thick . The side of the wrench marked "S" is for use on the socket side of the hose end. The side of the wrench marked "B" if for use on the swivel nut side of the hose end