Metal propeller (test type), for the Harold Hume Piffard Aeroplane E.N.V. Aero-engine type D (40hp)

Metal propeller (two blades, adjustable, test type), one blade damaged, unsigned, England, for the Harold Hume Piffard Aeroplane E.N.V. Aero-engine type D (40hp), V8 cylinder, 1910