The AF-ORING25 O-Ring fits 2nd generation Small / Point of Use ICS systems sold from October 2019.
2nd Generation ICS POU Water Treatment Systems include;
It is recommended to have a spare O-Ring at all times. This O-Ring will not fit 1st generation POU (Point Of Use) treatment systems.
Small / POU 2nd generation systems that use this O-Ring look like this. Please check that the overall length of your system is less than 15 inches.