GWS Hyper Drive 12x6 Propeller. GWS Hyper-Drive series props offer high efficiency and great value for your electric powered models. The Hyper-Drive series of prop have extra reinforcement in the hub area, which allows them to be run at higher RPM than the standard Direct Drive series props. The center hole of the prop is designed for a 6mm shaft, and the prop comes with a set of reduction bushings to adapt the center hole to 3mm, 4mm, 5mm, 6mm or 8mm prop shafts. According to the widely accepted Maximum RPM formula of 120,000/D for GWS HD series props, the 10x8 HD prop should not be used over 10,000 RPM.