[Fits multiple Black +Decker string trimmer models]: LCC140, GH400, GH500, GH600, GH610, GH900,GH912, ST6600, ST7000, ST7200, ST7700, ST7701, ST8600, ST9000, CST1000, CST1100,CST1200 and more [Compatible with Trimmers]: Designed for use with auto feedstring trimmers, This spool and cover are Spool a perfect replacement ，30-foot factory-wound replacement spool features a 0.065-inchdiameter line. [ Feed System Replacement]: Eliminatestime spent hand-winding string trimmers, compatible with stringtrimmer and utilizes centrifugal force to feed the trimmer line as it isneeded. Aerodynamic shape reduces drag for more efficient cutting. The line axis for the Black Black Weeder is flexible, allowing the line to stretch and cushion when hard surfaces are impacted, and increases cutting efficiency by 50%, allowing each spool to cut more weeds.