SEA and SEY FMA Fastmag For M4 MAG Heavy (5.56) Our shipping time is about 7-15 days, less than a month, sent by Beijing, China's capital. Made by high density polymer.size:5.56mm Reduces reload cycle time, slight twist draws magazine out easily for quick reload. Able to attach to any molle webbing vest, bag or backpack...etc. Quick release and easy to install.