We use these.
[Link: l-com.com]Yup, quite pricey, but the quality is hard to beat. It's fiberglass, so no knockouts. I find that drilling them is easy/clean enough, though.
(if you ever do try one of these, the holes in the backboard are #6x32)
Last edited by Grasshopper on October 20, 2017 17:51.