This is a Sticky Holsters Magazine Pouch known as the Belt Slider, model BS.
The Sticky Belt Slider is a horizontal elastic magazine carrier that slides onto a belt. It will fit most belts up to 1.75in. You can use the accessory slot to carry an extra magazine" knife" or tourniquet. The accessory slot also has their Sticky material to help hold smaller or smooth items in place. It is open ended so a variety of different sized items can be carried from a single stack .380ACP magazine up to a large double stack .45ACP magazine and everything in between.
Features:
Ambidextrous
American Made
Latex and allergen free
Multi-Use and Multi-Fit
Part of a modular system
Fits most belts up to 1.75"