1. 【Package Contents】 ： You will receive replacement spools for edger or with cap cover parts, each piece measures approx. 6.7mm * 6.7mm * 3.0mm, enough quantity can meet your long time use, and get replacement immediately. 2. 【Durable to use】 ： Cutting line spools are made of quality ABS spool and durable polyamide nylon thread, not easy to break, have longer service life, flexible and durable for you serve a long time. 3. 【Lawn Mower Accessories Compatible With】 ： This replacement lawn mower spool is compatible with Black and Decker GH3000, GH3000R, LST540, LST540B, suitable for varying terrain such as yards, lawns, gardens, etc. Please check the compatibility before purchasing. 4. 【Facilitates the tedious work】 ： The replacement spool of the automatic feeding system facilitates the tedious work of the hand winding spools; The grass eating spool line uses centrifugal force and aerodynamics to reduce drag and achieve fast cutting, help you save time and energy, and improve work efficiency. 5. 【Usage Precautions】 ： Please wear safety glasses and long pants when using this product to ensure your safety, and unplug it before changing, installing or removing any accessories; Please note that our product is only suitable for young grasses, do not use it to remove strong weeds.