I have something similar to this from Blackhawk. It's both a belt w clip on and converts to a shoulder rig with the included straps. Never used it because I got a dropleg which I like better and 2 vests with built in shoulder rigs.
"The difference between a successful person and others is not a lack of strength, not a lack of knowledge, but rather in a lack of will." Vince Lombardi
"No One, and I MEAN NO ONE Craps on me and Gets away with it!!! Those days are gone...