In the lower right corner are eight check boxes where you can select which subdetectors that will be shown in the picture of the event. The subdetectors are divided into two categories ("Barrel" and "Forward") depending on where in DELPHI they are located.
The top five check boxes show some of the subdetectors in the cylindrical shaped part of the detector. These subdetectors are best used when looking at the event from the angle selected by the End view button.
The three check boxes below show some of the subdetectors in DELPHI's end part. These subdetectors are best used when looking at the event from the angle selected by the Side view button.