This is the Main Gear without One-Way Bearing / for the Heli-Max AXE 400 3D. / / FEATURES: Nylon construction / White in color / / INCLUDES: One Main Gear without One-Way Bearing / / REQUIRES: Installation on the helicopter / / SPECS: Outer Diameter: 75mm (3") / Inner Diameter: 12mm (0.47") / / COMMENTS: Also available with One Way Bearing, HMXE8026.