A: The item you are asking about is for the CORE-Series salt systems.

If you have an older RJ30 Classic model, you would want this item: https://www.circupool.com/CircuPool%C2%AE-RJ-Classic-O-Ring-Set_p_109.html

If you have an newer RJ30 model, you would want this item: https://www.circupool.com/CircuPool%C2%AE-O-Ring-Set-for-RJNULSi_p_108.html Answer provided by:  Roger (10/1/2019)