This is a new, unused Safariland ALS holster for Glock 17/22 with M3, TLR-1, Surefire X200, or LAS-TAC 2 weapon lights.
This holster started life as a level 3, mid-ride holster. The level 3 retention devices were removed for 3 gun competition so it's basically a level 2 ALS holster with the single thumb button release.
The finish is the Safariland STX finish. The level 3 mechanism is not available but I'm sure could be acquired from Safariland directly if someone wants to turn it back into a level 3 retention holster.
This holster retails for $217 but is a deal at $100.