[Package Included]: 6 x Trimmer Spool Line,1 x cap,1 x spring.Premium weed eater string is 30 ft (9 metres) in length, 0.065" diameter .The total length of about 55m is suitable for long-term use. [Work with Models]:Fit Black Decker string trimmer GH900, GH600, GH400, GH500, GH610, GH912; ST6600, ST7000, ST7200, ST7700, ST7701, ST8600, ST9000;NST2018, NST2118, NST1118, NST1018, NST1024, NST1810; MTC220, MTE912; CST1000, CST1100, CST1200, CST2000; BESTA510, BESTA512, BESTE620; LST220, LST201, LST300, LST400, LST420, LST136, LST120, LST140, LST1018, LST522, LSTE523, LSTE525. [Efficient Cutting]:Replace the spool automatically, polyamide nylon line is durable and flexible, easily cuts through grass and weeds,no need to wind the spool manually. [Easy to Use]:This String Trimmer Spool is easy to use and easy to install. This trimmer product set also includes a spring and a spool cap. [ Guarantee]: has full after-sales service and installation instructions. If you have any questions, please feel free to contact us.