The shape and the colour of a button show the cell diameter of the box: a capsule is 40 mm, a rectangle is 3 inches, a crystal is 4 inches. The active box is in a deep colour, the rest are light.
A box name like «B54.003» reads as follows: 54 is the number of cells, 003 is the sequence number.
The box you picked last stands active at the far left - recent boxes are always at hand.
If the buttons do not fit on the screen, the bar can be scrolled; an arrow at the right edge shows that there are more boxes further on.