On the final diagram, there are triangular tabs above and below the main body of the unit. There are two flaps on the main body of the unit, into which the tabs from two other Sonobe Units may be inserted:
Original Image, click to view correct size: Sonobe Unit with folded tabs
The sequence of images below demonstrates how to create a cube using six Sonobe Units:
Original Images, click to view correct size: How 6 Sonobe Units can be used to form a cube
Using more Sonobe Units, it is possible to create a range of different shapes.