Red Eye’s OEM Petcock Vacuum Line outside tubing is Viton-B, which is not affected by sunshine, hot air or ozone. Viton-B has very good resistance to fuels with MTBE, methanol, ethanol, engine oil and coolant, and good resistance to DOT 4 brake fluid. Teflon FEP tubing is inside, to prevent collapse under vacuum. 2 nickel plated music-wire tubing clamps are provided for the ends. These clamps are of the Happy Fingers type, so you can use your bare fingers to squish them open.
Per popular request, the bend in the end of the vacuum line has been discontinued.