I've been buying these for a while now, I like the pot size & shape, but the clips don't fit my tanks... most of my tanks are late 70's early to middle 80's & have the plastic trim edge that has a ridge on the inside ( I imagine that originally there were plastic covers that fit these tanks, & that's probably why there is a ridge inside, though I think it helps keep things like snails, from climbing out of the tanks... I end up making my own clips for these, by drilling 2 - 1/8 holes, & bending a short piece of stainless wire into a hook... it took a few tries to get it just right, but they work good now... just seems like there must must be one similar that wouldn't require customization...