This is a modified twin drum magazine made for the MP5K. I received it from a friend. Apparently, they cut it in half because the twin drum magazine was too cumbersome when attached to the Kurts. My impression after using it is that it indeed doesn't get in the way. The magazine is loaded by winding the knob that sticks out from the back. I was fighting while taking advantage of the Kurts' lightness and maneuverability, winding it like crazy. It can also be used with Tokyo Marui's standard MP series other than the Kurts, but since it was made specifically for the Kurts, it's a magazine dedicated to the Kurts. Nowadays, 400-round magazines are also sold, so this is mostly a junk item. I'm selling it at a low price. If you're okay with that, please purchase it. No claims, please.