These fittings enable the conversion of any British style ⅜-24 bubble flare hardware to use -3AN line. Simply screw these fittings into your British style master cylinders, slave cylinders, calipers or wheel cylinders and you're ready to run AN lines! AN lines are widely available, and renowned for their dependability. The AN fittings 37° flare profile is incompatible with the British bubble flares 45° profile without these adapter fittings. When we couldn’t find these fittings anywhere, we decided to produce our own.