Compatible with Multiple Craftsman weed eater Models The weedeater string is Compatible with Craftsman weed eater models: CMCST900, CMESTA900, CMESTE920, CMZST98020, CMCST915, CMCST900D1,CMEST913 Series, Compatible string trimmer line Model: CMZST065 & CMZST0653. Cap Model: CMZST120SC. Premium Meterial-PA6(Nylon)+30%GF(Glass Fiber) Adding just the right proportion of glass fiber to the nylon material dramatically increases the stiffness of the weedeater string, enabling it to maintain stable performance at high rotational speeds and not easily broken, effectively extending their life. This is a feature not found in other ABS plastic weed wacker string. Perfect Fit Eventronic weed wacker string works seamlessly with the automatic feed system thanks to the precision design and dimensional fit of the string trimmer line assembly. The protective cover is fitted with a snap-fastening structure to ensure that the weedeater string is securely locked in place.