Flare nut wrenches are great tools when you are contemplating removing a fastener that you just know you are going to round off the corners with your regular open end wrench. If you take a close look at the wrench, part of the tool is removed so you can slip it over a brake line, etc. and have two additional surfaces to break the fastener loose. What's makes this set unique is the 300° pivoting head. This allows you far more access to a variety of hard to remove fasteners. Use these every time you think you could get yourself in trouble. Six Standard Flare Nut Wrench set includes: 1/4", 5/16", 3/8", 7/16", 1/2", 9/16". Six Metric Flare Nut Wrench set includes: 8, 9, 10, 11, 12, 13 mm. Case included.