Image Item No. Description  32125  Technic, Plate Rotor 3 Blade with Smooth Ends and 6 Studs (Propeller) Catalog: Parts: Technic, Plate  2712  Technic, Plate Rotor 3 Blade with Toothed Ends and 3 Studs (Propeller) Catalog: Parts: Technic, Plate  69984  Technic, Plate Rotor 6 Blade with Clip Ends Connected (Water Wheel) - Solid Studs Catalog: Parts: Technic, Plate