Usage Tips:Item Package Quantity: 10 Compatibility: Fits multiple Black + Decker string trimmer models including LCC140, GH400, GH500, GH600, GH610, GH900, GH912, ST6600, ST7000, ST7200, ST7700, ST7701, ST8600, ST9000, CST1000, CST1100, CST1200, and more. 1. Compatible with Black+Decker Trimmers: This spool and cover are designed specifically for Black & Decker auto-feed string trimmers. The 30-foot factory-wound replacement spool features a 0.065-inch diameter line, ensuring a perfect fit and optimal performance. 2. Feed System Replacement: Say goodbye to the hassle of hand-winding string trimmers! This replacement spool is compatible with Black+Decker string trimmers and utilizes centrifugal force to automatically feed the trimmer line as needed, saving you time and effort. 3. Enhanced Material: Made from premium 0.065-inch diameter nylon line, this spool supports fast cutting and offers a longer lifespan. (Note: This product is suitable for trimming tender weeds and grass. For tougher weeds, we recommend using blades.) 4. Package Includes: - 6 replacement trimmer string spools - 2 replacement spool caps - 2 springs Upgrade your trimming experience with our reliable and efficient replacement spools!