Printed in laser sintered nylon and designed to rotate around the central shaft. It is not printed with thread and those will have to be tapped or tapped and Helicoiled (other model designed for that). The base hole is 8.8 mm in diameter and will need to be tapped for the Atom shaft. It can also be used on 12 mm shafts, but, the hole will need to be drilled larger
For the Helicoil version click here.