Built from the ground up with first-rate parts & materials, the HK UMP GBB airsoft gun is part of our Elite Series of products and earns its keep in our flagship line with a high-strength polymer body, and adjustable hop-up. While many airsoft guns feature 3 standard shooting options (Safe, Semi, and Full-Auto), the HK UMP GBB airsoft gun features a fourth option: 2-shot burst. Double-tap your opponents to your heart's content! Don't let the fun end at 30-rounds. Pick up some extra HK UMP gas Mags to stay in the fight. While you're at it, be sure to stock up on Elite Force Fuel, our premium green gas, to keep your HK UMP fully charged and ready for action. Licensed Trademark of Heckler & Koch GmbH