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 standard props are made from ABS plastic with a glass fiber fill for extra strength and durability, and come in Black, Green and Orange colors.
The 9x4.7R props have a 6mm hole drilled in the front side of the hub, and an 8mm hole on the back side of the hub to accept a prop shaft adapter ring. Also included with the prop is a set of four 8mm OD adapter rings that step down the center hole of the prop to allow it fit on 3mm, 4mm, 5mm or 6mm 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.