Thomson's Carbon MTB bars are made with three different fiber types for strength, durability and long times in the saddle. The MTB Carbon Trail Handlebar is built for strength with enough flex built in for all day comfort. It's strong enough for all mountain/trail riding and light enough for racing. The bars are made with three different fiber types with different tensile strength and tensile modulus, including high strength carbon fibers. This helps to allocate stiffness and flex where needed. The bars are molded with an EPS mandrel inside to avoid wrinkles inside the layup during molding. Most other bars are molded over inflated nylon bladders. All carbon fiber material is produced by Toray and uses tailor made nano Epoxy Resin for very high impact resistance. Toray is the main supplier of carbon fiber to Boeing and Airbus. 1.5K woven impact ends help prevent damage to unidirectional fibers from shortening the bar or impact with the ground. With a light weight and precision tolerance clamp sections, it's the best bar for your Thomson X4 stem. It's also certified to EN, tested to DIN+. Friction Paste recommended for installation