Mernickle.
http://www.mernickleholsters.com/The model is PS6SA.
Worn with a good stiff belt, like one from Gunners Alley, it makes a real sweet carry set-up. The guns ride high and tight, and do NOT flop around.
Taken in a mirror, so the image is reversed:

Check out this pic, also taken in a mirror, they work well as crossdraws as well.

The gun on the right in this pic is a Ruger.