Original OEM Marquis Spas replacement filter to fit Marquis Spas e-series year models 2010-present. This Marquis replacement filter is specially designed to work with Marquis e-series spas providing the absolute highest performance filtration possible. This filter does not have threads on the bottom! Please see the detailed photos above! Feel free to call us at (972) 317-1011 if you have any questions about the replacement filters for your Marquis Spa!