In 2015 at the music fair in Frankfurt, Germany, Tombo presented the new Mu-01 (µ-01) and Mu-01 PG (µ-01 PG).
The novelty of those instruments is a new slide mechanism Tombo called “new Short-Cross-Key function”. As Tombo describes, it is as a revolutionary, newly designed slide for quick and effortless movement. As you press the slide the holes close from both sides. In addition there are 2 springs to keep it balanced: