This Speed-Feed Hi-Capacity Head Trimmer is the fastest loading bump-to-advance style head on the market. It can be reloaded without disassembly in 30 seconds or less - there is no need to press in stiff tabs or unlock covers just to re-load line. Compatible with SRM-225i, SRM-225i, SRM-230, SRM-266, SRM-266S, SRM-266T, SRM-280, SRM-280S, SRM-280T, SRM-225U, SRM-266U, SRM-280U, SRM-410U. | ECHO Speed-Feed Hi-Capacity Trimmer Head