This pouch is open no lid, mag is secured with pressure from Cordura reinforced with PVC, which adds stiffness. Inside the pouch is a special pressure foam that is built in the material to retain mag during hard activity. It also provides for quick reloads. 2nd Generation pouch comes with a hi-cap mag pouch sewn to it for a pistol mag, secured with elastic. Pistol Mag sits low enough that M4-30 round mag can be quickly removed without interference. THIS IS A GREAT POUCH FOR TACTICAL PURPOSES.