The Oregon 91712 is a high-quality, durable mower blade designed for Simplicity lawn tractors and zero-turn mowers with 20-inch cutting decks. This standard blade measures 520.7 mm (20-1/2 inches) in length, 57.15 mm (2-1/4 inches) in width, and has a thickness of 3.81 mm (0.150 inches). It features a 15.875 mm (5/8 inch) center hole and 9.525 mm (3/8 inch) outer holes with a 63.5 mm (2-1/2 inch) center-to-center spacing. It serves as a direct replacement for multiple Simplicity OEM part numbers, including 1708228, ensuring reliable performance and a precise cut for a range of compatible models.