Octura 0955 : 3 Blade for scale use. Reverse rotationDiameter: 2.17" (55mm) Total Pitch: 0.9x2.17 = 1.953" (45.9mm)Shaft Size: 3/16" (.187) (4.75 mm) ATTENTION: Right-hand rotation. These spin clockwise when looking at them from the back of the boat. Used for twins or boats that require opposite rotation than normal.