During the first3 years of WWII, German troops complained about a disturbing number of malfunctions with their Maschinenpistolen. One of the most common problems was dirt and dust entering the magazines, which could cause the follower to stick against the sides resulting in a mis-feed. To combat this, ribs were added to the magazines and a special rectangular brush was made specifically to clean the inside.

Officially adopted in August, 1942, the Reinigungsbürste für Magazin MP. The bristles are made in a rectangular cut, specifically to fit the inside of MP38/40 magazines. To use, the magazine is disassembled by removing the floor plate and follower. Then the brush is attached to the cleaning chain from the RG34 cleaning kit and pulled through the magazine body until all dirt is removed.

The brush is fits perfectly inside the loading tool, which is carried in the small side pocket of the magazine pouch.

Imported

Fits MP38 and MP40 magazines.

Will it work for GSG "MP40's"? No idea. I do not have one of those to try it out on.