The Worx 19” Lawn Mower Mulching Blade is a replacement blade so you can keep returning nutrients to your lawn with your Worx mower. The dual-edge NutriCut design provides natural fertilization while you mow, making keeping a healthy lawn easy. It’s compatible with the following electric and battery-operated mowers: WG719, WG720, WG770, WG771 & WG772. It is capable of being sharpened, significantly extending the lifetime of this blade. Just check with a local hardware or home improvement store, or a professional in your area for sharpening options. Or, if you have experience sharpening lawn mower blades, detailed instructions are in your mower’s owner’s manual. And the instructions for installing this blade are conveniently printed right on the packaging. Worx electric & battery-operated mowers are the cleaner and cost-effective way to cut your grass. They’re less expensive to power and maintain than gas mowers, and run quieter, too. Innovative Worx engineering has made them capable of more power and performance than previous generations of electric and battery-powered lawn mowers. So you’ll be happier with the results and enjoy a healthy and lush-looking lawn.