Yard chores just got easier with the new SharperBlade weed wacker and Trimmer blade from Sun Joe. The SharperBlade 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 SharperBlade cuts like a mower blade. SharperBlade’s self-sharpening system gives you the reliability and convenience you demand from your garden tool. After each trimming session, SharperBlade 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 SharperBlade SB600E/SB601E Trimmer/Edger only.