Suitable for Black Decker: Fits most trimmer models: S TC1820, STC1815, ST4525, ST5530, STC1820PC, EPC, STC1840, EPC, ST1823 etc. Quality edger line: 9.15m edger line can achieve larger mowing range with 1.65mm diameter, polyamide nylon yarn is durable and flexible. It is not easy to break, which ensures continuous work. Quick and clean cutting: The replacement spool of the automatic feeding system facilitates the tedious work of manual winding spools. It uses centrifugal force and aerodynamics to reduce drag and make fast, clean cuts. Perfect replacement spool: They are a perfect replacement for most original Black Decker spool models such as A6481 , A6485, AF-100, AF-100-3ZP, AF-100-BKP, AF-100-2. The coil can be inserted and removed without tools, and the operation is simple. At the same time, damage to the device is avoided and the thread is optimally used. Great value set: the package includes 6 spare trimmer spools, 1 spare cap and 1 spare springs. Coil cap replaces RC-100-P cap, spring replaces RC-100-P spring. Excellent value for money.