I cut a hole in a 5/8 plywood just enough for this bowl to fit in. I used a cardboard sheet to create my template. I reduced the diameter during first cut and reduced it slowly until the bowl fit tight.What this did was, I didnt have to screw the bowl down as that seemed to the point of failure for others. And I didnt want any sharp stuff jutting out on the surface.Used a couple of heavy duty L brackets from hardware store and mounted below the window.Between the cat tree and this bowl, our teen kitten spends most of his time in this bowl - watching outside the window or even sleeping.Until now, the bowl hasnt come loose, despite our kitty doing all sort of acrobatic stuff on/in it. If it does, Im planning to use some sort of acrylic safe adhesive to bond the lipping to the plywood.Best purchase ever!