Our Black Denim truck stacks are coated with an industry proven high temp silicone ceramic coating, they are heat treated and safely packaged before they are shipped. Black denim stack come in 5",6",7",8" diameters and lengths of 36",48", and 60 " in flatop, miter cut, aussie and bull hauler stack styles. Our black exhaust stacks are the best available. If we do not have what you are looking for please contact us. We have a huge inventory of exhaust stacks, systems and accessories. Black Denim truck stacks will usually ship out the within 24HRS UPS ground.