Damon
Great accessory!
I was looking exactly for something like this to fill in the gap between the top of the filter wall and the bottom of the lid there is a 1/2" space that things could fit through that this beautifully clips on and covers up. No one would know other than the tank owner it is easy to adjust and has premade spaces to be cut out for wave pump cords or tubing so it is very nice additional piece to have and I would highly recommend it for those looking to fill this area.