prevent under-the-couch tennis balls

I printed these to mount home depot yardsticks under our couches so that the little tennis ball addict dog of ours cannot roll them under the couch. these brackets allow the yardsticks to sit about 3 inches back under the couch so they aren't very visible and they are not going to easily get kicked and destroyed. I have 2 yardsticks in the front and one on each exposed side of both of our couches.