Shrimple Sponge Tank Divider - 55 Gallon

I ordered this for a guppy and pleco breeding tank because I found other dividers did not provide adequate separation. This divider works well. It's big enough and puts a tight seal all around, it even goes all the way to the top brace in a 55. If you can, install it before you set up the aquarium, because it's difficult to install in an already established one. You may want to cut it down vertically because it puts upward pressure on the center brace. I don't know if that's going to be a problem or not, but it is noticeable.
The reason for the four star review is because from the time I ordered, it was almost over a week before the product was shipped and then another couple days of shipping before I received it. It wasn't packed very well, and I had to do some work to unkink it. Fortunately it straightened out in the aquarium. It's about 3 inches thick, which seems to be overkill, but like the title said the divider works better than anything else on the market without having to silicone in components.

These dividers are excellent quality and perfect fit, but in my opinion, they are a little overpriced. I need three right now, but I could buy 4 10 gallons tank for almost the same price