2 blade brass "Michigan" propeller. 9/16 prop shaft size. 6 3/4 diameter. Pitch is 9 1/2". Marked RM16? Prop has been extremely worked over. Examine photo. Uses a rear pin mount. Note: All pitch sizes are measured at the center of the blade. All sizes quoted are approximate and may vary slightly. Sizes quoted, eg, 10 1/2-10 3/4 means the blades are not equal. All propeller sales are final. Ask questions first before buying.