The Sundance 6540-501 R is a compatible replacement for the following spa filters:
The Sundance Spas 6540-501 Comp. Pool 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 Sundance Spa filter measures 8 1/2" x 14" and includes 80 sq. ft. of media area. In addition, this pool filter cartridge is constructed with a Closed top hole and 2 1/8" Open bottom style.