The left navigation works like a filter on the bottom list. To find quickly your wanted product do the following:

• Choose your federation
  The list below shows products from the selected association. Because the IJF/EJU have only one product (the back number) you will be directly forwarded to the configurator of the back number.
• Choose your product
  The list below shows only products of this association. Since IJF / EJU has only one product (the back number), you end up directly on the back number configurator.