|RCS Vanguard 2 w/Glock 19.|
It's basically nothing but a little clamshell guard over the trigger, and a belt loop. Its biggest downside is that there's no real way to "reholster", should you have to draw it for real. You'd have to remove the holster from your belt, pop it back on the gun, and stick the whole assembly back into your waistband.
On the other hand, for administrative on-and-off purposes, removing the whole gun and "holster" assembly from your trousers is as simple as popping one snap (or un-threading one belt loop, depending on where on your belt you carry; whichever is quicker).
It also comes with a piece of string that you can substitute for the belt loop and strut arrangement; you tie it off to the hole in the bottom there and then loop it 'round the belt.
Using a looped shoelace to make a "holster" is sometimes referred to as an "OSS holster", since back in WWII, our guys running around behind enemy lines would tuck their 1911s and Victory Models inside their drawers that way. If needed, they could toss the gun and not have an incriminating holster left on the belt for the bad guys to find. We still have guys in the Army doing stuff much like that, but they don't often carry 1911s or Victory Models anymore, hence the genesis of the above holster.
While not a general-purpose everyday carry kind of holster for me, I've found it perfect for days when my errands are going to take me through No-Toting Zones, since it goes on and off almost as quickly as just stuffing the pistol down your trousers, while giving the security of a belt loop (as opposed to clips or J-hooks, which just don't give me the warm-'n'-fuzzies.)