I love them and have them on every single intake in every tank I have, canister and HOB. You can get them much cheaper at kensfish.com . http://www.kensfish.com/atipondandprefilters.html . The adapters it comes with fit my eheim, rena xp3, and my aquaclears. Water flow is great.
Yeah, I know they're cheaper elsewhere, but that was the only place I could find a decent picture. *shrugs*
Thanks for the review. I'm very much thinking about replacing my aquaclear sponge prefilters with these, because.. well, let's admit it, it's just prettier.
I love mine...it's big and bulky (I hide it behind some driftwood), but I like the black better than the AC sponges and I've been rinsing it vigorously weekly since last June with no signs of wear yet.