1. Product Description Material: Nylon Dimensions: 6.7mm × 6.7mm × 3.0mm Quantity: 3 pieces Package contents: 3 combat heads 2. Package Contents You will receive replacement spools or cap - covered parts for the trimmer. Each piece is approximately 6.7mm × 6.7mm × 3.0mm in size. The sufficient quantity can meet your long - term usage needs and allow for timely replacement. 3. Durability The cutting spool is made of high - quality ABS spools and durable polyamide nylon line. It is not easy to break, has a longer service life, is flexible and durable, and can serve you for a long time. 4. Compatibility with Lawn Mower Accessories This replacement lawn mower spool is suitable for models GH3000, GH3000R, LST540, and LST540B of Black and Decker. It is applicable to different terrains such as yards, lawns, and gardens. Please check the compatibility before purchase. 5. Simplify Tedious Work The replacement spool with an automatic feeding system simplifies the tedious work of manually winding the spool. The lawn mower spool uses the principles of centrifugal force and aerodynamics to reduce resistance and achieve rapid cutting, helping you save time and energy and improve work efficiency. 6. Precautions for Use Please wear safety glasses and long pants when using this product to ensure your safety. Before replacing, installing, or removing any accessories, please unplug the power plug first. Note that our product is only suitable for tender grass and should not be used to clear thick weeds.