Pentair Rainbow Dynamic Series II Top Load High Flow Spa Filter, RTL-25 (R172510, 1.5"") includes a high quality 25 sq. ft. filter cartridge made with 3 oz. Reemay fabric for Pentair. Plumbing ports on the bottom are 1.5"" FPT or female threaded. Also available in Slip connections (non-threaded), see part number 2-172500.
Pentair RTL-25 top load spa filter can be installed into a 6.5"" niche for topside access, or installed under the spa, angled so that the cartridge can be removed. Filter assembly includes body, lid with air relief and handle, lid closure ring with lock tab, and lock nut to secure to spa when installing as a top load spa filter, with access from outside the spa.