it's about 14" tall and 9" wide. What kind of tank are you using it on?
if the xp3 is the right size for the tank then it should fit. However I just realized it doesn't even fit in the cabinet for my 135g because of the hoses. The hoses aren't exactly the kind you can be twisting and turning. They will kink. You're pretty much going to have to either get different hoses that'll fit, or just deal with the xp3 sitting behind the stand rather than in it.