It is good and does last 3 to 4 yearsThis is not a "fun" purchase because it's an expensive part of owning a hot tub with the ACE system. However the new cell arrived very quickly and was easy to install. The ACE system immediately recognized the new cell and it was working right away. No more blinking green light and it's making chlorine from salt! Thanks.Fit and worked perfectlySo far salt cell is generating good chlorine levels. Hope it last several years!My Watkins Ace unit quit working well before a year on our new Hot Springs tub. Warranty wouldn't cover new unit. Unfortunately the Scepter unit wasn't for sale here on Amazon so I got stuck paying $700 plus for the Watkins unit. Now you can buy the Scepter unit for $239 on Amazon. Hot Springs Watkins should be ashamed of themselves ripping people off with poor designed products like the Ace Cell. Go with the Scepter unit if you need a new unit and save a bunch of money. I won't be buying another Hot Springs spa or recommending one to anyone with the poor service they provide. There are better choices.Product works as expected. Shipped the next day. All worked out well.Easy to swap out.Do not order from this supplier!!! This product did not work from the very beginning and they would not correct the situation. They never replied to my concerns. I have ordered thousands of products on amazon and this is the worst product I have ever bought.