The Bullgear CNC Hop Up for A&K/Cybergun/Classic Army M249 Gen 3 is available now at Airsoftjunkiez... "This isn't just a replacement CNC hop up for A&K, Cybergun and Classic Army M249. Made out of full metal so it will last longer and give you the edge in accuracy. It is designed for the Prometheus Purple hop up rubber, or other lipless hop up rubbers. Once the barrel is connected to the chamber itself, there is absolutely no wobble at all which increases it's reliability. Modern hop up chambers uses a spinning dial to adjust the hop which is far more reliable than previous versions and will account for more precise adjustments."