Compatibility: The type D pool and spa filter is compatible with Summer Escapes, Funsicle, Bestway and for Intex D Type filters. for canisters: SFS-350, RP-350, RP-400, RP-600, RX600, SFS-600. All part numbers and names are for compatibility purposes only. Superior Filtration: Meltbown technology allows for superior filtration over the standard pleated material used in most pool and spas, meltblown filters also keep the debris locked into the material, keeping your pool cleaner without the use of chemicals. Perfect Fit: Our type D pool and spa filters measure 4.1” x 3.75”. You will get 4 premium type D pool and spa filters and excellent after-sales service. 100% American Made and Sourced. Filters Tested to NSF 42, 61 and NSF 372 for drinking water standards, because why shouldnt your pool water be as clean as your drinking water? Will Not Work with Summer Waves Model Pumps Melt blown filters are designed to hold a significant amount more dirt and particles than a pleated filter. Melt blown filters will also filter down to a much lower particle size than a pleated filter giving you a much cleaner pool without the use of chemicals. Spend less time worrying about your pool and more time enjoying it.