Oregon 65-221 Blade Adapter Lawn Mower Replacement Part Oregon 65-221 Replacement MTD Blade Adapter 5/16" side hole Splined for riding mowers 1985- 1988 Riders series 200, 400, 500, 600, 700, 800 Replaces MTD 753-0210, 748-0235, 748-0283, 7480300B, 7480300, 748-0300B, 7480300B, 7530583