G-SONIC PRO series of propellers has its origins in the G-SONIC series of propellers. The proven blade design has been retained and the use of high resistance modern plastic has led to an increase in torsional strength, bending strength and tensile strength. This has made the GRAUPNER SONIC PRO series even more efficient as the propellers are able to generate more thrust at reduced noise levels. Graupner G-SONIC PRO propellers are designed and manufactured drawing on the very latest knowledge and using state-of-the-art CAD/CAM systems and machines. This precise approach to design and manufacture optimises the concentricity and blade tracking achieved by the propellers.Hub diameter 23.3 mm Hub thickness 14.4 mm