I did not know what it was because I actually ordered a pool vacuum and down my order there were noted: this article could complete your order !! Outside, I did not pay attention and I fell into the "trap" so these filters do not correspondes to my pool, luckily I have acquaintances who are very interrested by this product. All that to say that may be the filters are very good but not useful for my pool vacuum. A little longer than details will be welcome, thank you Amazon for the quick delivery of all same.
