Waterco MT-301 AM Tool, Socket Set, MTJ-770-S/MT-50-S/MT-100MT-301 AM (All Metal) Includes 3 lightweight sockets and upgrades the original MT-301 Value Pack trio by removing the polycarbonate MTJ-770 and MT-50, replacing them with the stainless steel models MTJ-770-s and MT-50-S. Also includes the aluminum MT-100 double-hex socket. MTJ-770-S for use on: Sta-Rite System 3 models 75 and 110 Systems equipped with 3" knobs only MT-100 for use on: 7/8" hex nuts 9/16" hex nuts Purex Triton Nautilus Pentair American Products Hayward Pro Grid and Micro-Clear series. MT-50-S for use on: Sta-Rite pumps, Posi-Flow filters, Mytilus, Pentair, R.G. Ray, Pac-Fab, Qwik-Clean, Paramount, Cal-Pump, Wet Institute, Caretaker, and Pool Valet.