This pouch is open, no lid. Mag is secured with pressure close cell foam. Cordura is reinforced with PVC, which adds some stiffness and flexibility. Specifically cut at the right height. Mag will be retained during hard activities, such as running, jumping, kneeling, going prone, crawling, etc. It also provides for a quick reload. You will find them better than any Kydex mag pouches. Heavily stitched for lifetime abuse and use. Great use for competition, tactical training.