Amazon.com Product Description:
The Black & Decker string trimmer Auto Feed System replacement spools provide 30-foot replacement lines for use in your auto feed string trimmer. These factory wound spools offer maximum reliability and eliminate the hassle of having to wind the spool yourself. The exclusive Black & Decker Automatic Feed Spool (AFS) system automatically advances the cutting string without bumping, using centrifugal force to feed the trimmer line as it is needed. Using the correct diameter line is critical to the performance of your string trimmer -- these spools feature a .065-inch diameter line and are designed for use with the following Black & Decker string trimmers: #GH400, #GH500, #ST6600, #ST7000, #ST7700, #CST1000, #CST2000, #NST2018. These spools are sold in a 3-pack to save you time and money and are backed by a 2-year full warranty.