"LIGHTWEIGHT" - 0.10 - 0.12": Lighter than conventional HD Truck Exhaust flex, yet when you inspect & handle it, it seems only slightly lighter than normal. Excellent exhaust performance in warm climates, and when used in various industrial & agricultural applications. Available in Galvanized, Nickel Plated, & 409 Stainless."STANDARD WEIGHT" (Heavyweight in Stainless) .018-.020": This is Flexatube's standard thickness & is generally recognized as the industry standard flex weight. Some suppliers though, will use lighter Flex their "standard". Available in Galvanized, Aluminized, 400 & 300 Series Stainless."HEAVYWEIGHT" - .023 - .025": Available in Galvanized & Aluminized. Very tough flex tubing which offers longer life & better sound attenuation"EXTRA HEAVYWEIGHT" - .028 - .030": Flexatube offers this - the heaviest flex in the industry! Super durable & extra noise control - this is serious flex tubing!! Available in Galvanized.