Auto Supplies Direct 3/16" tube nuts pack of 10 are for use with any brake line, including steel, Poly Armour, and NiCopp for the repair or replacement of hydraulic brake lines. These fittings are commonly used on automotive applications where long stretches of brake or fuel lines need to be run with a standard inverted flare, also known as a double flare. For use on most domestic brake or fuel lines. Auto Supplies Direct fully stands behind the quality of all their products, therefor, we offer a full money back guarantee if you are not fully satisfied with your purchase. Total of (10)3/16" Standard Inverted Flare Tube Nuts Most Common SAE Inverted flare / Double Flare Size For Use With 3/16" Steel, Poly Coated or Copper Brake Lines Commonly used for fuel line or brake line replacement Contains Fittings You need to Repair a Leaky 3/16" brake or fuel line Auto Supplies Direct Satisfaction Guarantee.