The QRS mid-cap magazine is an airsoft AEG magazine designed to fit VFC M4 series and HK416 magwell. You'll likely find it fits a variety of other M4 platforms as well. For such a simple unit, there are quite a few features packed in to enhance your airsoft shooting experience. The magazine features diamond hexagon composite reinforced ribs for enhanced control and dexterity, anti-skid texturing for positive grip, a reinforced easy-grab floor plate designed to assist in quick extraction from your magazine pouch during reloads, and even comes with a magazine numbering area on the base of the floor plate as well. Made of high-strength polymer, the 120-round VFC QRS mid-cap magazines are built to last for reliable performance.