Very - it's non-brittle plastic. I'll get a shot of the backside when I get home (pegboard, ahem) it has slight extrusions on the back where the holes are so that if you were to mount it on a wall as intended it would sit off of the wall enough to be able to insert the pegs (ok this is getting me too hawt) - which is very cool since it will not be sitting flush against the bottom of your cage. Hell you could probably throw this stuff in the dishwasher.