Check the listing for details. Spa Filter for SofTub -8555 Microban Replacement- fits Pre-2009 softtub Models. Condition: New. Listed at 41.95 USD. Spa Filter for SofTub -8555 Microban Replacement- fits Pre-2009 softtub Models Clarathon Premium Ultra Filters: the most effective, durable pool & hot tub spa filter cartridges. These blue media filters feature Antimicrobial protection which lasts for the life of the cartridge, & inhibits the growth of bacteria that can foul and weaken a cartridge. Antimicrobial filters are easier to clean and less prone to odors & staining than ordinary filters. When changing spa water, always rotate the soiled ones out with clean, dry spares. The result is longer filter life and no waiting. Product notes: Pre-July 2009 Softub with offset 4" collar. Antimicrobial media protects the filter cartridge, and is not a water sanitizer. Verify correct spa filter dimensions by measuring old filter. Measurements may vary from specifications by about 1/8" or more due to expansion, shrinkage, or manufacturer's variances. Filter Specifications: Diameter: 6" Length: 7-1/2" Top: Closed Bottom: 4" Snap-on Collar Surface Area: 35 SF Antimicrobial Premium Replacement For: Other: 5015, 5015CA, 8555, 2005400