In examining other magazine extensions on the market, engineers at Area 419 noticed that many of them were simply rectangular extensions that didn't fit the natural curve of the magazine. They've solved this issue with the Area 419 AICS, ARC Magazine Extension. The Area 419 AICS, ARC Magazine Extension is cut with an attachment point that matches the angle at which the magazine curves. This ensures that rounds contained in the magazine travel straight into the extension without any kind of binding or other obstacle. Additionally, the extension features exterior fluting that provides added grip for quick magazine changes. Available in black, blue, gunmetal gray, raw or red colors ARC, AICS and Accurate magazines receive room for up to 5 more rounds Accurate WSM magazines receive room for an added 3 rounds Each Area 419 AICS, ARC Magazine Extension are compatible with a number of AICS or Accurate Mag magazines on the market designed for standard bolt-face calibers or SAUM/WSM magazines.