400mm Carbon Fiber Tube Size and Shape. Rounded tube with 3mm outside diameter, 2mm inner diameter, 400mm overall length. Pultrusion. Pultruded tube means that all the fibers are in one direction, which makes it stronger than the woven tube in tension. Lightweight. 1.5g/cm3(1.5 Gram per cubic centimetre) in density, strong as metal but only one fifth in weight. Corrosion-resistant and heat-resisting. Smooth surface. Made from high tensile and modulus unidirectional carbon fiber, with polishing finish. Application. Pultruded carbon fiber tube is used for racing drones, RC helicopter wing, RC airplanes and RC sailboats, kite spars. Tube Shape: Circular PipeOutside Diameter: 3mmInner Diameter: 2mmOverall Length: 400mmFinish Type: GlossyPackage Content:2 Pcs 3x2mm x 400mm length Carbon Fiber Tube