This is a Fobus Holster known as the E2, model SWBG.
The next step in the evolution of holster design. One piece holster body construction with adjustable retention screw allows the user to customize the holster retention pressure.
Features:
Passive retention, one-piece holster body construction
Retention adjustment screw with passive retention
Protected sight channel
Low profile design for concealability
Reinforced rivet attachment