The SFT 45/90 is an ambidextrous selector that can be set to either 45 degree or 90 degree. Use with corresponding receiver markings. It is compatible with both AR 5.56/.223 and AR 7.62 /.308 platforms. Instead of having either a 45 degree or a 90 degree selector, you can choose to switch between settings. This safety selector is incredibly smooth and has a super crisp lockup.