Quick release Delrin bolt for easy cleaning and maintenance; Ported/Honed 12" one piece barrel for increased accuracy (Bore size 0.685); Semi-automatic firing; CO2 and compressed air compatible; Double finger trigger with safety switch; Spare O-rings and Allen Keys; Safety HK Army barrel cover with adjustable elastic band; Adjustable clamping feed neck to ensure that the loader is properly secured to the top of the marker; Patented internal gas through grip gives a more ergonomic feel while firing the marker; Easy adjust chrono located on the back of the marker with lasered +/- to ensure the chrono is adjusted properly