Aquaswim CF50 and Hurlcon QX-50 and other replacement filter cartridge.
Has a flat top and bottom with a open hole at each end.
Filter dimensions: Height- 370mm(end to end), Width- 185mm, Hole ID- 75mm.
Also replacement for Quiptron 464/Pantera PCF50/Poolrite EnduroEC50/Spa-Quip C50 S2000/ Monarch Eco Pure 50