This filter functions as part of a set with the Master Spas Legend Range Inline SMART Filter and Sani Stream Pod. Thoroughly check the dimensions listed for any filters you intend to purchase. Our recommendations are suggestions and should not be taken as guarantees. Once you receive your filters, do not remove the protective hygienic wrapper until you confirm they fit your spa. The wrapper must be completely intact for us to process a refund if the filter does not fit. Castle Hot tubs recommend cleaning your filters once a week with a product like AquaFinesse Filter Cleaning Tablets. If your spa is not in continual use, wash the filters on alternate weeks instead. Keep a spare set of filters for alternate usage. Castle Hot Tubs is a well-established, trusted name in the water care industry. We strive to ensure your purchasing experience with us is pleasant. If you are not 100% happy with our service, we will rectify it, so please contact us directly before leaving negative feedback. Thank you! Postage: We dispatch goods as soon as we receive payment. Orders placed before 1 pm are sent out the same day. Our couriers deliver from Monday to Friday. Orders placed on weekends or bank holidays are posted the following working day. For delivery to the Scottish Highlands & Islands, Isle of Man, Scilly Isles, Channel Islands, Northern Ireland, or outside the UK mainland, please contact us for a postal quote before making your purchase. Thank you.