Yard chores just got easier with the new Sharper Blade weed Wacker and Trimmer blade from Sun Joe. The Sharper Blade replacement blade quickly gets your yard work done without the hassle and frustration of traditional string trimmers. Engineered from durable nylon embedded in polymer, the Sharper Blade cuts like a mower blade. Sharper Blade’s self-sharpening system gives you the reliability and convenience you demand from your garden tool. After each trimming session, Sharper Blade replacement blade wears down to expose a fresh, new edge, ensuring a precise cut every time. 216 ft. of nylon string in every blade. Replacement blade for Sun Joe Sharper Blade SB600E, SB601E and SB602E Trimmer/Edger only.