From 2010 to 2018 The Marquis Eseries Spas used this open ended 37 Sq.ft hot tub filter cartridge. It cross references to the Unicel c-4326 which is a very common cartridge used in the hot tub industry.
This spa cartridge measures 4 15/16″ in diameter and 13 15/16″ in lenth with 2 1/8″ opening top and bottom.
As we are a Marquis Spa dealer in Massachusetts we stock the Microban coated option OEM # 20364. This helps bacteria and mold build-up inside the pleats which keeps the cartridge lasting longer.