Grey Charge Air Cooler hose. These silicone couplers are made for serious pressure conditions. They have a full 5 layers of high-temperature cording and are 5-5.5 mm thick, giving these couplers a burst pressure of 290 PSI. They are made from pure silicone, giving them an operating range of -40° to 482° F. Also available in 3", 3.5", 4" & 4.5" in Red, Blue and Grey at www.siliconehosecoupler.com or call (410) 360-7105. Also a complete selection of any silicone product that you would need.