GemFan produces some of the finest propellers for Multi-Rotor use, and they are available in a variety of colors and materials. All of the different sizes are available in both normal and reverse rotation as needed for use in multi-rotor craft. The High-Strength props are are made from Nylon with Carbon Fiber fill for an extremely stiff blade that will not deform under load. These props are about 10 times stiffer than the normal GemFan Multi-Rotor props.
The 4x4.5 props have a 5mm hole drilled in the front side of the hub. Included with the prop is a set of OD adapter rings that step down the center hole of the prop to allow it fit on 2mm, 3mm, or 4mm motor shafts. If you have a larger threaded shaft on your prop adapter, the center hole can be reamed out to a larger size as needed.