RYOBI 42” ZTR Replacement Blades are the perfect solution for replacing dull or damaged blades on your RYOBI ZR3 Zero Turn Riding Mower. These blades are two times more durable, delivering premium cutting performance and longer blade life. They are designed to be used for side-discharge and mulching. Remove the deck in just 60 seconds to easily replace blades.  For best results, replace your riding mower blades after 25 hours of use. The 42” ZTR Replacement blades are designed for the RYOBI ZR3 80V HP Brushless 42” Zero Turn Riding Mower (RY80HPRM04-ZR3) and include (2) 21” Mower Blades and Operator’s Manual.