Sun Joe SharperBlade Trimmer/Edger OEM Blade quickly gets your yard work done without the hassle and frustration of traditional string trimmers. Engineered from durable nylon embedded in polymer it cuts like a mower blade and it's self-sharpening system gives you the reliability and convenience you demand from your garden tool. Replacement blade for Sun Joe SharperBlade SB600E/SB601E trimmer/edger only. Safe on brick concrete and stone