Rear mount pressure gauge replacement Fits Pentair Star Polymeric, FNS, SM & SMBW 4000/2000 Series, Nautilus, Nautilus Plus, Star pool and spa D.E. filters Also fits Pentair Meteor, Sand Dollar, Meteor Top Mount, Tagelus, Tagelus II pool and spa sand filters and Pentair Sta-Rite Cristal-Flo II high-rate sand filters Compatible with Pentair Triton C-3 pool and spa commercial filter models TR100C, TR140C and Six-way 1-1/2-inch HiFlow valves