Gearbox/Gearcase Assembly compatible with Echo String Trimmers, Weed Wackers, Weed Eater. Fits all models with 26mm shaft diameter and square drive cable.
Many compatible models include: SRM210, SRM225, SRM230, SRM2300, SRM2100, SRM260, SRM280 and many more. Note that for the Echo trimmers, they have changed the Gearbox on the newer machines to no longer have the grease port. These have the grease port. They also changed specifically the SRM225 so it no longer has the 2 screws on the outside, and it now matches this style.
You may have to drill a new hole in the shaft to align with the set screw, due to slight variances. I have installed these on several Echo machines without any functional issues.
Compare your part against the photos to confirm, and please reach out if any concerns.