240+lbs Arch Support Inserts for Men Women, 3/4 Carbon Fiber Heavy Duty Orthotic Shoe Insoles for Plantar240+lbs Arch Support Inserts for Men Women, 3 4 Carbon Fiber Heavy Duty Orthotic Shoe Insoles for Plantar Why Carbon Fiber: Crafted with high strength, ultralightweight carbon fiber, these arch support inserts weigh 50% less than traditional materials, ensuring all day comfort without the bulk. With a tensile strength 5 times that of steel, 3 4 carbon insoles form a rigid yet flexible "bridge" across your foot. The dynamic elasticity of carbon fiber