RAM-MOUNT -RAP-B-202-225 - 2 x 2.5 Base with 1 Ball

I was planning on sticking a Gopro mount to the underside of this mount, expecting it to be solid and flat like the metal ones made by Ram. Sadly, it is hollow underneath with strengthening ribs in a "Union Jack" sort of pattern. No good at all for my needs. Will be returning it.