Video released by Airsoftjunkiez showing you how to install the Redline N7 Milsim Edition HPA Drop-In Kit to a Krytac Gearbox. This kit is a true closed bolt and fully mechanical HPA cylinder replacement. It is weatherproofe and does not require any battery or FCU and less joule creep as compared ot other HPA engines for airsoft... "Defcon Leader shows in depth details of how to install a Mislim N7 into a Krytac gearbox."