For FlexRip users, the easiest way to see what screens you have is to go to your Rip dispatcher.
Choose Options > Queue Defaults.
Click the Screening tab. You will see a pull down menu showing the list of dot shapes.
For the Imaging Engine (powered by APPE) users, the screens are centralized on the Automation Engine Server. So, you can see the (unified) list of dot shapes for all Imaging Engine PCs you have. Any screens that you have, but are not selectable at this moment, are greyed out with the reason why between brackets (see e.g. SCR02 in the screenshot below)