Construction: These unique up pipes are constructed of 2" mandrel-bent 304 stainless steel tubing with a .120" wall for strength and durability. 2" Inner Liner Flex Pipes: The up-pipes utilizes heavy duty 2" flex tubes with internal inner liner. Leak-Free Seal: High quality 3/8" thick flanges are used for a complete 360 degree sealing surface. Note: This is a "Race Only" product used solely for competition. Its use is limited to closed-course and open-course racing that is formally sanctioned by a recognized racing organization. Any other use including recreational off-road use could be in violation of local, state and federal laws.