Short for automatic electric gun, AEG is a type of battery powered air gun capable of full & semi auto firing. An electric motor inside the AEG rotates a series of gears sequentially to drive the piston, which in turn compresses the spring. When the spring is released, the piston is being pushed forward to produce compressed air and propel the bullets. Due to such a complex internal structure, power upgrade is never easy.There is no substitute for good old fashioned know how. By upgrading the gun yourself, you are knocking out the hardest part of it first, knowing what goes where.The 2020 Edition of this book presents new concepts and practical skills reflecting the latest changes and trends in the airsoft industry. New technologies such as Electric Programmer, Electric Blowback, Rapid Deploy Pistol and Electric Recoil Gun are also included in the coverage.After trying out the tricks and tips suggested in this book, never hesitate to contact us should you believe there are mistakes waiting to be corrected (there are always better ways of doing things…).