The Waterway WW 817-0125N R is a compatible replacement for the following spa filters:
The Waterway 817-0125N Comp. Pool Filter Replacement is a pool filter replacement that features 4" Open top and bottom holes with 125 sq. ft. of total media area. This compatible Hayward filter measures 8 15/16" x 23 5/16" and purifies the water in swimming pools and spas.