There are inherent vulnerabilities in die cast and metal spoked wheels. Everyday use requires the tool to handle some rough treatment without dents and bending. Not all wheels are up to this. Our solution? Invent a new material. Introducing Kesonite, a strong, dense metal/resin composite. It holds its shape better than metal and it's stronger than a spoked or die cast wheel. The weight of the wheel makes it easier to use and more accurate in rough terrain. The RR30 & RR40 will measure in feet and inches.