The ECHO YOUCAN Speed-Feed 400 Cap and Spring Maintenance KitGo to product viewer dialog for this item. is a genuine OEM replacement kit designed to keep your outdoor power equipment running at peak performance. This do-it-yourself kit restores proper line advancement and prevents line feed issues on your trimmer head without requiring professional service fees or a full replacement head. The kit includes an authentic replacement lid, compression spring, and spring cap built from high-quality materials to withstand demanding residential or commercial landscaping environments. It is compatible with all ECHO SRM trimmers equipped with a Speed-Feed 400 trimmer head, as well as select compatible models from Shindaiwa and EGO. Consistent upkeep using this maintenance kit helps prevent premature wear, avoids costly repairs, and significantly extends the service life of your equipment