These are optional Carbon Main Rotor Blades for the Thunder Tiger Mini Titan E325 Helicopters.FEATURES: Carbon construction, balanced and drilled Black incolor Stiff and stable Designed for stable flying as well as aerobatics INCLUDES: Two carbon main rotor blades REQUIRES: Attaching to main rotor assembly SPECS:Length: 325mm (12.8") Chord: 32mm (1.26") Weight: Approx. 22g (0.78oz.) Root Thickness: 4.5mm (0.18") Bolt Hole Diameter: 3mm (0.12") Airfoil: Symmetrical