This mod adds additional 5 quality levels that go between base game ones.
It's normal, normal+, uncommon, uncommon+ etc. It also increases the chance to jump more quality levels to make getting to end ones less costly/frustrating.
This is not balanced and you can get much more powerful than in base game since Rare+ quality here is like Legendary in base game.
Legendary+ is about 2x as powerful as in base game.