Geonox Airsoft checks out the Lancer Tactical M4 SD ETU MOSFET if it is up there with other AEGs from other brands that have similar features. Video is in German... "Here I introduce the Lancer Tactical M4 SD with ETU, Mosfet and spring quick change system. The ETU protects you from jams. The mosfet spares the internals. And with the spring quick change system you can adjust your energy. I'll show you the highlights and what I like about it. Although I recommend a Lipo, the Sparfüchse will be particularly happy. With the included Nimh battery and charger you can start directly."