3-1/2″ ID. 3.9″ OD. The ultimate in extra thick soft wall silicone quality with very high temperature performance and extra long service life. Exceeds SAE J2006-R1, and ABYC & NMMA P-1 exhaust standards. Glossy Blue “Very Hi Temp” has 4-6 ply polyester reinforcement and 350� F (177� C) Maximum. Used world wide on premium boats, yachts and special service vessels. It has become the super yacht standard. 10 year warranty. Length 3′.