A. Product Description Material: Nylon Dimensions: 6.7mm × 6.7mm × 3.0mm Quantity: 3 pieces Package contents: 3 combat heads B. Package Contents You will receive replacement spools or cap - covered parts for the trimmer. Each piece is about 6.7mm × 6.7mm × 3.0mm in size. The quantity can meet your long - term usage needs and allow for timely replacement. C. Durability The cutting spool is made of ABS spools and polyamide nylon line. It is not prone to breakage, has a relatively long service life, is flexible and durable, and can serve you for a while. D. 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. E. 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 relatively rapid cutting, helping you save time and energy and improve work efficiency. F. Precautions for Use Please wear safety glasses and long pants when using this product to enhance your safety. Before replacing, installing, or removing any accessories, please unplug the power plug first. Note that our product is more suitable for tender grass and may not be used to clear thick weeds.