Speed Feed 400 ECHO Trimmer Head Part #99944200907 (If you purchase this head and cannot get it installed here is a link to a video explaining how) How to Replace Your ECHO Head This head doesnt come with adapters for other machines. This head is strictly for ECHO straight shaft SRM model trimmers! If your machine has SRM in the model number...this head will fit!! Also fits PAS models with the straight shaft trimmer attachment. It will not fit PAS models with the curved shaft attachment. INCLUDING BUT NOT LIMITED TO: SRM-140SRM-200SRM-202SRM-210SRM-220SRM-225SRM-225iSRM-225USRM-230SRM-250SRM-251SRM-260SRM-261SRM-265SRM-266SRM-280SRM-300SRM-302SRM-303SRM-311SRM-330SRM-340SRM-343SRM-350SRM-400SRM-402SRM-500SRM-501SRM-1500SRM-1501SRM-2010SRM-2090SRM-2100SRM-2110SRM-2200SRM-2201SRM-2300SRM-2301SRM-2400SRM-2410SRM-2450SRM-2500SRM-2501SRM-2502SRM-2510SRM-2530SRM-2601SRM-3000SRM-3001SRM-3010SRM-3100SRM-3110SRM-3400SRM-3410SRM-3500SRM-3550SRM-3800SRM-4600