Size: 10AN male flare to 5/8 inch, the thread size of the 10 AN is 7/8-14 UNF. Fits to 5/8" OD hardline, please measure before purchase. Material: Made of aluminium alloy fitting and brass ferrule. Sealing: The AN thread of the flare is sealed by a 37 degree angle. Application:This 5/8 compression to 10an fitting is widely used in fuel delivery, fuel system, engine modification, etc. Note:Only applicable to stainless steel or aluminum hardline.