This is one of oldest leveling items in-game. By that I mean that right clicking on it will increase it's QL, should you meet the requirements, instead of equipping it. To equip it you need to left click on it and drag it over to wear window.
Now, if you have already visited Eye Mutants, chances are that you got your hands on a Massive Steel Body Armor. This is used to build male only (no ladies or troxes), NoDrop armor. But since it exists in QL 10 to 50, building it shouldn't be any problem for any handy-man.