This is a Glock Holster known as the Sport/Combat, model HO02639.
A super lightweight ambidextrous holster is extremely durable and easily concealable. The simple design of the Sport/Combat holster secures the pistol with the trigger concealed.
Features:
Polymer construction
Fits belts with 1.25-2.50 widths
Fits Glock 20/21 w/trigger guard
Ambidextrous
