These AN fittings are made from aluminum and received a black anodizing surface treatment. Black fittings are very modern and neutral, and won't stick out in the engine room of a streetcar. They are often used for motorsport track racing, drift, drag, and tractor pulling. We recommend you watch the video guide located on the main AN fittings page, for instructions on how to put the fittings together. We carry are a larger selection of fittings in black, than any other color, as it's the most popular color by fare. So if your going for the red or blue color and cant get everything you need, consider going for black instead.