[Compatible models]: Compatible with Greenworks SINGLE LINE weed eater string trimmer Cap: 21332, 21222A, 21602, 21062, 21132, 21242, 21282, 21312, 21302, 21342, 21362, 21262, 2100202, 2100302, 2100702, STBA40B210, ST40B410, BST4000, ST40L00.

[Professional CNC winding spool Cap]: Compatible with green works 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. The product is only suitable for young grasses. For strong weeds, use other tools such as blades to trim.