This is the underside of the cabinet. Both will fit although it’s rather a snug fit.@Jeffcb let me elaborate on the size of this UV. I can’t remember the rule of thumb for the number of watts per gallon but Aqua Ultraviolet company rates this 13 Watt for a 75 USG system. Their 8 Watt unit they rate for a 70 USG system at least that’s what BRS says on their product description. I went for the 13 Watt it was only about $30 more but I have a custom sump that’s around 21 USG + DT 54 USG = 75 G. Today I’m going to take the housing of this uv and the shelves I made before applying another paint coat and make sure I can get both inside the cabinet. I’ll make a post on it.