B001QYGRI8 Unicel UHD-SR137 Swimming Pool and Spa Filter Cartridge Replacement for Sta-Rite WC108-70S2X Cartridge in Sta-Rite 135TX, 135GPM-TX, 135TXR, and PTM-135 Filters

Make sure this fitsby entering your model number. CLEAN AND CLEAR: Keep your spa water clean with this replacement filter cartridge (part number: UHD-SR137) DIMENSIONS: Measure 8-11/16 inches in diameter and 31-1/4 inches tall FILTER MEDIA: Features fine filter media with 221 pleats that can cover up to 37.5 square feet END CAPS: Features open top end cap with 4-3/16 inner diameter and open bottom end cap with 12 concentric slots and 4-3/16-inch inner diameter