Elite Force H&K UMP .45 Gen 2 Airsoft AEG Electric Blow Back SMG - Black Holsters & Gun Cases In Techt's testing they found

In Techt's testing they found that changing to a different spring (lighter spring) caused issues with the cyclone feed loading correctly

Radial Ramping Face Design- the Hush Bolt features a "Radial Ramp" on the leading edge of the bolt face which allows for less ball stack clipping

The Board is the soul of every electronic marker

Applicable for LiPo and Li-Ion battery pack

Hose-less Design

Elite Force H&K UMP .45 Gen 2 Airsoft AEG Electric Blow Back SMG - Black Holsters & Gun Cases In Techt's testing they foundFeatures Durable and lightweight nylon reinforced polymer construction with stamped H&K licensed trademarks Side folding stock allows for easy stowage and compact carry Front 20mm accessory rails are ideal for mounting weapon lights, vertical grips and other accessories, the integrated 20mm top rail is ideal for a wide variety of optics Functioning mock charging handle and bold enhances realism and makes hop up adjustment easy Extrememly realistic