It's the best UMO project item in the game. Stacking all the UMOs that fit your build on it will basically create an item that is very hard or impossible to outdo. Of course the item is rare and obtaining UMOs legit is difficult, so it's an endgame item for those who want to perfect their build.
Or if you don't want to bother with finding/trading for UMOs you could always give it to your low level alt character, and that way they have an armour that scales with them as they level through normal MOs and makes the progression faster & easier.