Waterway Square Spa Skimmer Skim Filter [1 1 2" x 2" Spigot] [10 Sq. Ft.] (510 1600) jonardindustries replacing the pack is often replacing the pack is often the clearest path back to confidence The Raypak 337A Combustion Orifice Plate (010340F) is a replacement combustion orifice plate for compatible Raypak pool and spa heater applications This Waterway assembly is a good replacement option when the original square spa skimmer and filter needs full renewal with the same general plumbing format and filtration size this Waterway square skimmer and skim filter is a practical option when a 10 square foot unit with 1 1 2 inch by 2 inch spigot compatibility is needed