Spool Specification: : Compatible with Black&Decker string trimmer spools, 20ft 0.065 inches,RS-136 / RS-136-BKP / 143684-01.Compatible with Black Decker string trimmer models: CST500, CST800, GE600, ST1000, ST200, ST300, ST3000, ST400, ST4000, ST4400, ST4500, ST5000, ST6500, ST6800.Cap model: 682378-02.Professional CNC winding spool: : Compatible with Black Decker spools by the CNC machine cutting and winding, automatic line change. Manual winding is cumbersome and can easily get stuck during use, which can cause damage to the string trimmer.Rugged material: : High-quality ABS spool & durable polyamide nylon thread, flexible and long service life. Use centrifugal force and aerodynamics to reduce drag and achieve fast cutting.Precautions for use: : When you using this product, protective measures should be taken to avoid damage to the body caused by spilled wires.