Discontinued Fullmetal Echo1 AR-57, an M4 that toploads using P90 mags. Retailed for about $300 new. Never fielded by muself, has sat aside. Using a slightly modified V2 gearbox, this rifle is basically a M4, besides a proprietary gearbox shell, and nozzle alongside the proprietary Hopup assembly. Included unknown Holographic sight & front buis 3x P90 midcap mags (2 68rd/1 120rd) Wired to deans this rifle, is preupgraded internally by Airsoft GI (don't know what besides deans battery connector). Asking $200 + shipping and PayPal fees.