This is the optional Century Helicopter Rotor Tech 710mm A-Tip Carbon Helicopter Blade Set. FEATURES: For .60 size nitro powered helicopters Symmetrical airfoil designed for 3D competition Layered carbon fiber for optimum aerodynamic damping Endorsed by multi-national competition winner Scott Gray INCLUDES: 710mm A-Tip Carbon Helicopter Blade Set with four 1mm washers, four 2mm washers, two 5mm to 4mm bushings and two 3D decals REQUIRES: Installing on helicopter SPECS: Length: 28" (710mm) each blade Grip: .5" (14mm) Width: 2.4" (62mm) Bolt Hole: 4-5mm Weight: 6.4oz (182g)