【Compatible with Multiple Craftsman weed eater Models 】 The String Trimmer Spool Cap is Compatible with Craftsman weed eater models: CMCST900, CMESTA900, CMESTE920, CMZST98020, CMCST915, CMCST900D1,CMEST913 Series. Cap Model: CMZST120SC. 【Perfect Fit 】 Eventronic protective Trimmer Spool Cap is fitted with a snap-fastening structure to ensure that the weedeater string is securely locked in place. The perfect size significantly reduces the risk of trimmer line breakage and improves the stability of the machine by 40%, making it easy to handle all types of mowing tasks. 【Auxiliary Effect】 The trimmer Spool Cap can protect the trimmer from stability and correctly fix the spool, preventing weeds from entering and avoiding damage to the trimmer. 【Easy to Install】 Each weed eater spool cap cover can be replaced easily in a few seconds. It is very easy to assemble and remove, just unscrew the old cap and snap the new cap into the spool line by hands, ready to use in seconds,no need other tools. Please turn off the weed wacker before installing for removing the cap cover. 【Inclued】4 pack String Trimmer Spool Cap,4 Spring. As a professional professional weed whacker string spool & cap supplier, we have an excellent after-sales service team to answer all your questions. CMZST120SC String Trimmer Spool Cap for Craftsman Weed eater CMCST900, CMEST913, CMESTE920, CMZST98020, CMESTA900, CMCST915, (4 Cap, 4 Spring)