SUITABLE FOR MULTIPLE COMPATIBLE WITH BLACK+DECKER MODELS: GH400, GH500, GH600, GH610, GH900, GH912, ST6600, ST7000, ST7200, ST7700, ST7701, ST8600, ST9000, CST1000, CST1100, CST1200, CST2000, MTC220, MTE912, NST1018, NST1024, NST1118, NST1810, NST2018, NST2118, LST120, LST136, LST140, LST201, LST220, LST300, LST400, LST420, LST522, LST1018, LSTE523, LSTE525, BESTA510, BESTA512, BESTE620 EFFICIENT CUTTING: 0.065-Inch durable polyamide nylon thread (30 FT. long/pcs), flexible and long service life. Use centrifugal force and aerodynamics to reduce drag easily cuts through grass and weeds HIGH QUALITY: Pliable and flexible allowing for the line to stretch and cushion on impact with hard surfaces. Automatic feeding system to change spools eliminates the time-consuming task of manually winding the line. Makes mowing the lawn easier and more convenient ABRASION RESISTANT: The trimmer line is made of improved nylon polyamide material with a tensile strength of over 100 lb, which is 30% more durable than other brands and lasts longer MORE DURABLE: The spools are made of the latest materials to withstand the high speeds of the weed wacker, resulting in higher durability Weed Eater Spool for Black+Decker,Line String Trimmer Replacement Spool, 30ft 0.065" Autofeed String Trimmer Line,Suitable for Black+Decker String Trimmers (12 Replacement Spool,3 Spool Cap,3 Spring)