Blue Force Gear
Blue Force Gear Flapped Ten-Speed M4 Triple Magazine Pouch
Three M4 magazines side-by-side, each secured by its flap.
The flap
An adjustable elastic flap covers the top of the pouch and secures to a hook-and-loop strip on the front. This is what sets it apart from an open-top Ten-Speed: the magazine cannot fall out on its own.
And if you don't want it, the flap is removable - on one pouch, several, or all of them. You then revert to a classic open-top Ten-Speed pouch.
The elastic
Military-grade elastic, in service for over ten years. When empty, the pouch remains flat, about the thickness of a coin according to the manufacturer: nothing to snag on.
Origin
The Ten-Speed was designed for confined spaces - buses, trains, watercraft - where a protruding pouch becomes a problem. Hence the philosophy: a pouch you forget you're wearing.
This version holds three magazines. Magazines not included.