Black & Decker AF-100-BKP Grass Hog Replacement Spool in a Bag Grass Hog replacement spool for BLACK+DECKER auto-feed trimmers Factory-wound spool eliminates winding hassles .65-Inch diameter provides durable, efficient cutting action 30-Feet replacement line fits models GH400, GH500, GH600, ST6600, ST7000, ST7700, CST1000, CST2000 and NST2018