"It's 3 pcs ""Chway"" brand String Trimmer Replacement Spool cap cover(Cap Model:2958002),Compatible with Multiple Greenworkss String Trimmer - Applicable models are listed below:#2101602,#2101602A, #STBA40B210, #BST4000. Note: None of the models are suitable for use with other hayrides than those listed above! Professional Styling - Our replacement caps are green round caps with a diameter of 2.95in and a cap height of 1.265in.Our spool cap cover is designed to hold the spool in place securely and correctly, ensuring that your trimmer works as it should. Made of High Quality Materials - PA66(Nylon)+G30(Glass Fiber).Adding just the right proportion of glass fiber to the nylon material not only dramatically increases the stiffness of the caps, but also enhances wear and heat resistance, effectively extending their life.This is a feature not found in other ABS plastic caps. How to confirm the suitability of your lawn mower - you can find the model code in the product nameplate on the head of your lawn mower; you can check the instruction manual of your lawn mower to find out the model number of your lawn mower; in addition, we provide presales consulting service for our products.