Available on all domestic orders. Your info is safe with us. Umarex Heckler & Koch UMP GBB Blowback Airsoft Rifle. Naturally, we went ahead and licensed several models for airsoft, including this exquisite gas blowback version. Built from the ground up with first-rate parts & materials, the HK UMP GBB is part of our Elite Series of products and earns its keep in our flagship line with a high-strength polymer body, folding stock, adjustable hop-up, functional bolt release as well as the signature HK-style charging handle. While many Airsoft rifles and submachine guns feature 3 standard options (Safe, Semi, and Full-Auto), the HK UMP GBB 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. No hustle searching for compatible accessories! This is the perfect Airsoft Rifle for you. Great for a present! Full/ 2-shot / Semi Auto. High strength polymer body. Umarex Heckler & Koch UMP GBB Blowback Airsoft Rifle Specifications. 17.75-27.25 in. If the wrong contact details are provided any losses incurred as a result will be the buyers responsibility. INTERNATIONAL BUYERS – PLEASE NOTE.