Hyperion 40-class Straight Gear These are the same size as in the original YAK54 40e ARF, but made of high tensile spring aluminum. Use as replacements for the YAK54 40e, or to fit your own models in the 30e to 70e classes. Weight: 70g, Width: 300mm (between axle holes), Height: 190mm (to axle holes). Includes mounting hardware and two aluminum wheel collars as pictured. Hyperion