The Waterway 817-0040 R is a compatible replacement for the following spa filters:
The Waterway 817-0040 Comp Pool & Spa Filter Cartridge is a pool water filter designed specifically to reduce unwanted contaminants in swimming pool and spa water, and to improve clarity. This compatible Waterway filter measures 4 15/16" x 11 1/4" and includes 40 sq. ft. of media area. In addition, this pool filter cartridge is constructed with a 2 1/8" Open top and bottom styles.