Pentair 273512 Bleeder with O-Ring Replacement Pool/Spa Filter and Valve Bleeder replacement Fits Pentair Nautilus and Nautilus Plus pool/spa D.E. filter models NS24, NS36, NS48, NS60, NS72, NSP-24, NSP-36, NSP-48, NSP-60, NSP-72 Also fits Pentair FNS pool and spa D.E. filter models FNS 24, FNS 36, FNS 48, FNS 60 Also compatible with Pentair Triton C, C-3, TR100C, TR140C pool/spa sand filters and Six-Way 1-1/2-inch HiFlow pool and spa multiport valves Includes o-ring; measures 4-inch length by 6-inch height by 2-1/2-inch width