This is the replacement Upper Rotor Gear for the Heli-Max Axe CX nano (HMXE13**) FEATURES: Nylon construction Black in color INCLUDES: One Black Nylon Lower Rotor Gear Two 1.2mm x 3mm Round Head Screws REQUIRES: Installation SPECS: Diameter: 23.6mm (0.93") lgm 01/31/11 ir/jxs