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Part number would be cool
When I'm a stickler for the exact OEM item or part # , I do usually exhaust google search. In many cases these days and especially so with older model 'stuff' , any number of after market companies can make a replacement or substitute item "that works" and that definition itself can be less than confidence inspiring. In my case, I have filters and extras so I can source the part by dimensions if needed and if no part # is on the filter base. I looked up the J 400 series manual a few weeks ago and although I didn't scour it, I didn't see any ref to part #'s and it may be the J-400 series booklet is a bit too generic to be useful. In a case like this and as Jacuzzi Jim mentions, I'd use a local dealer or get one on the phone and ask about the part for your model and also where they get that ref info from such as an owner manual ? or service manual ? If it's truly a genuine Jacuzzi part, that would help instill confidence for me too. Once you have that info it should be easy to cross ref or triple check by any other means,,, amazon.com , mail order tub part suppliers etc... all via the home computer, phone or ?? At this point, you'll see others comments, ratings, mentions of price, possibly other ref info like other brands that may work just as well and be cheaper ….I rarely buy anything without some sort of double checks or verification and I'm usually price shopping anyways so I'm already tied into a few sources. Sometimes you do see a viable option that is well rated and a lesser priced way to go along the way.