I cannot praise these black oxide coated steel brake line tube nuts enough! Never have I purchased a product that has exceeded my expectations quite like this one. The quality of the materials used in these nuts is exceptional and the black oxide coating ensures that they are durable and long-lasting. Installation was easy and straightforward thanks to the precise threading and fit of these nuts. I will definitely be purchasing more and recommending them to anyone who needs brake line tube nuts. Thank you 4LIFETIMELINES for creating such an outstanding product that truly delivers!