The o rings provide special inner barrel stabilization

in the magazine

retractable stock with easy access to the battery compartment

Airsoft gun includes orange tip (not pictured)

HK MP5 SD6 KIT High Power Airsoft The o rings provide specialElite Force and Heckler & Koch team up to make one sweet MP5 SD6 airsoft SBR. Included in the box is an easily installed A4 style stock that allows you to customize this MP5 to your liking as well as in installed claw type Picatinny Optics rail. Of course the retractable SD6 stock is still fully adjustable and fully collapses for ease of maneuverability. This slick AEG sends . 20 gram BBs downrange at 315 FPS and works great with your 7. 4 11. 1 LiPo