There are a few different types of airsoft fields. Open area and close quarters indoor are among the most popular. Once you choose the type of play format, you need to find out the proper power limit. For open airsoft field play in the US 350FPS (1.14J using 0.2g BBs) is the most common. For indoor play, the allowable FPS is much lower - 300 or less (0.84J using 0.2g BBs) in most cases. In the UK the requirement is pretty universal - it is approximately 1J (using 0.2g BBs) across the country. We teach you exactly how to build and configure an AEG mechbox to reach and meet the UK/EU 1J power limit, with the goals of high efficiency, reliability and durability. HIGH SPEED GEAR SET AND SINGLE SHOT MODIFICATION ARE ALSO COVERED IN-DEPTH. With our step by step guidance you are going to turn your mechbox into a long lasting performer.