Magpul Industries Maglink, Magazine Coupler, Fits PMAG and M3, Black MAG595-BLK The MagLink is a coupler for PMAG 30 and 40 round AR/M4 magazines which allows the user to attach two magazines together for more efficient speed reloads" and to keep additional ammunition accessible on the weapon at all times. The MagLink features a two-piece bolt on design and durable" lightweight reinforced polymer construction.