The BLACK DECKER string trimmer auto feed system (ABS) replacement spool eases the tedious work of hand-winding spools. Designed for use with BLACK DECKER auto feed string trimmers, the 30 Ft. factory-wound replacement spool features a 0.065 In. diameter line utilizes centrifugal force to automatically feed the cutting string while eliminating bumps and hitches. The ABS replacement spool is compatible with the following BLACK DECKER string trimmers: #GH400, #GH500, #GH600, #ST6600, #ST7000, #CST1000, #CST2000, #NST2018.