This is a bracelet generator. The bracelet is made of loose square rings linking to the rings next to them in the style of chainmail. Using the customizer you can define the lenght and width of the bracelet and you have some control over the size of the individual rings.
This idea of the chainmail rings comes from http://www.thingiverse.com/thing:45203, by Walter but it has been reimplemented in openscad.
The customizer allows you to select the length and width of the bracelet. It is recommended that you start by printing a very short (40 mm) and narrow (2 rings) bracelet first to see how this thing prints on your machine. If needed you can increase the separation space between individual rings a bit in the customizer to see how well it works. To test the clasp I suggest you cut this short test bracelet in 2 and test if the ends are working well together. Then measure the circumference of the target arm and create the bracelet according to taste. Most bracelets will need to be around 15-25 cm and this may be a challenge for some build platform. So a rotation parameter in the customizer help you to put the bracelet along the diagonal of the build platform.