The Ryobi OEM Height Adjustment Knob Assy RY401011VNM is a replacement part specifically designed for the Ryobi 40v Cordless Lawnmower. This knob allows for easy height adjustment on the walk-behind lawn mower, which is propelled by hand and features a brushless engine. Being cordless and powered by a 40v battery, this model offers convenience and efficiency for maintaining your yard and garden. Perfect for those looking to keep their lawn looking neat and well-groomed without the hassle of cords or gas-powered engines.