After opening the page of the article you are interested in, you will find a table showing all the pieces available for that item, in the lower part of the page, right underneath the photograph.
The table shows technical information about each piece, and each column is provide with arrows that allow to order the pieces according to the desired criteria (piece length, price, unit price).
The table has a scroll bar on the right side that allows you to view all the available items. If you do not find the mentioned features, try switching browsers or emptying your browser's cache.
Once you have identified the item you need, select it with the appropriate BOX at the right end of the row and click the "Add to Cart" button at the bottom of the page. The piece will be added to your cart; you can complete the order by proceeding with payment or you can go on with your shopping and select other items.