Compact, simple, efficient: a must have - MDT AICS Short Action Magazine Loader

Unlike an AR-15 style rifle mag the AICS mag loads like a pistol mag.
If you use a similar device to load pistol magazines you appreciate how it depresses a magazine follower.

This loader works the same way in that it depresses the follower to give you just enough clearance to slide each round into the magazine under the feed lips.
WITHOUT this loader, your thumb forces each round in and under the feed lips against the full tension from the magazine follower spring. Many a thumb sliced open on those feed lips. Not an issue with this loader.