you can stack up to a maximum of four units. smaller units must be stacked above larger units.
to fit the clip:
1 place your unit on a flat surface.
2 fit the clip across the top of the unit, as shown in figure 3 (picture 1), ensuring that the longer sections of the fastening pieces are pointing downwards.
3 align the fastening pieces over the slots found on each side of the unit.
4 push the clip down gently to secure it, ensuring the fastening pieces snap into the slots on the unit.
to fit another unit:
1 rest the second unit on top of the clip and align it with the front of the unit below.
2 press down gently on the unit to secure it onto the clip, ensuring the fastening pieces fit into the slots on the unit below, as shown in figure 3 (picture 2).
figure 3 stacking your units together
to remove the clip:
1 remove the top unit together with the clip. if you hook a finger around one of the the fastening pieces and then pull it gently from out of the slot, the clip should come away with the upper unit attached to it.
2 push the clip in the center, so it bends towards the base of the unit, and then separate once the clip is loose.