Constructed with premium metal alloy, the M4 Reinforced Gearbox Frame provides superior resistance and a prolonged lifespan for your replica. Every detail is carefully considered and thoroughly tested by Lonex, ensuring reliability and quality. This solid and durable frame, equipped with 8mm ball bearings, significantly enhances the performance of your gearbox. Designed for M4/M16 replicas, this V2 version frame weighs 350g and is manufactured by Lonex. It comes with a polycarbonate selector plate, tappet plate, six bearings, and screws.