Yes, they are thinner. It is not flush with the mag well, but it does not stick out as much as the standard ones. About half the thickness (or less) of the standard .350" one.
The Wilson Combat website should has some pics of it I believe. If you see a mag that has a black base plate that is not as thick as the standard ones you have, then that is it.
The Wilson Combat website should has some pics of it I believe. If you see a mag that has a black base plate that is not as thick as the standard ones you have, then that is it.