Blue Davey CF & Monarch EcoPure Series Cartridge Filter Lid Locking Ring. Fits the CF Series Cartridge Filters sizes 50, 75, 100, & 150. Part number 1 in diagram. Do not confuse with the later & larger locking ring listed here. Suits this 220mm lid. Also suits some older Enduro, SpaQuip, Hurlcon and Aquaswim cartridge filters.
- Outside Diameter: 250-mm
- Inside Lip Diameter (thread): 226mm