A&K 2500 Rds Electric Drum Mag works for MP5 Replica

This magazine is super easy to use, holding an impressive 2500 rounds, and you don't even have to wind the spring manually.
It has a switch that can be turned off completely. When set to AUTO, it continuously loads BBs into the hop-up chamber, which is handy when using the replica in Full Auto mode. Another cool feature is the Sound Control - the magazine starts feeding BBs when it senses gearbox activity.

The magazine runs on a regular 9V battery, not included.