The McCauley two-bladed, constant speed propeller is used on Cessna, Beechcraft and may other light single-engine aircraft. The blades are easily moveable by hand. Avotek also offers this McCauley propeller in a cut-away version that has been carefully crafted to show the internal parts and workings.
McCauley Light Plane Propeller P13
McCauley Light Plane Propeller Cut-away P12
McCauley Three-Bladed Propeller P38