I notice this is in the Roborovski thread? My main concern would be the vertical height for a robo?
They have long, thin and speedy back legs, so how does your little one get down without problems? Tubes are generally best at a safe angle rather than straight up and down like that.
Is the tube going up to the housing area as long as it is in the image? If it is, I would try and shorten it or use a corner tube into the unit and the longer tube running at an angle to make going in and out easy. Crittertrail tubes are fine for a robo, but not vertically as they pose a real danger if the robo falls down inside the tube.