For use with the EGO Commercial Series String Trimmer, STX3800. This trimmer head holds the spool which has a capacity to hold up to 29of .095 trimmer line. This greatly reduces reloading. With the easy wind design you have more time to get the job done.Replacement bump head,Trimmer spool holds up to 29of .095 trimmer line,Genuine EGO parts ensure compatibility and quality,Specifically designed for EGO commercial series string trimmers and brush cutters: STX3800, STX4500, BCX3800, BCX4500