These work and fit well singularly, but suffer from the same issue as the cat6 keystone (PID 1044) in that they cannot be fit side-by-side in some of the 6-keystone wall plates. The style that is not flush type (for example PID 6550) will fit side-by-side without issue.
PROS: Cheap. Good quality. Nice fit and finish.
CONS: Don't fit next to each other in some wall plates.