That image is very old and is of a version discontinued 5 or 6 years ago. I haven't seen one like that since very early on. Our current SKU is EU385CF-1S which, for some inexplicable reason is incorrectly shown on Solid Signal's web site as "Discontinued Not Available". We have several hundred in inventory.
See this document for an example of how it's used:
http://www.antennasdirect.com/cmss_f...d%20UHF%20.pdf