Aircraft Model(s): 55 Baron. Applicable Engines: IO-520-C, -CB. 1 - STC Document Set SA02561CH-D, 2 - Polished Spinners C-3567-9P, 3 - 3-Bladed Propellers PHC-C3YF-2UF/FC7391D. 75 inch diameter 3-bladed, "Scimitar" aluminum hub propellers.