Better done to it, of course, than the teak-faced plywwod! (Now have an extra hole in it, as it is.) The end of the panel shown is for the Kenwood head unit, which is pretty square. The S-H radio template has 10mm radius corners. I'd drilled 5/8 holes in the corners to try it out. which included two on the wrong end. Would work fine with square corners, but then I need an opening for the sabre saw blade, anyway.