ROTORTECH 515mm CARBON BLADES EPSpecifications: Length: 515mm Width: 48mm Grip Thickness: 10mm Hole: 3-4mm Airfoil: Symmetrical Tip: Aeroflat Make: Carbon Fiber Common Application: 30 size Electric RC Helicopters Includes: 1x 3D/holographic decal sheet 2x spacers 4x 1mm thick washers RotorTech‚Ñ¢ Standard Features: Safety wire runs alone the inner core of the blade. This keeps the blades in one piece upon a crash to insure safety to pilots and bystanders. Low parasitic drag coeficient due to the efficient airfoil and top quality clear resin finish, insures more engine power is transferred for lift, speed and more crisp maneuvers. High density D-Spar of Carbon Fiber mixed with a special resin absorbs all high-g spanwise loading. Designed for your 3D performance. Mathced C.C.G. for stability. Matched outward S.C.G. for better autos. Airfoil designed for fast, accurate cyclic. Layered for optimum aerodynamic damping.