With all due respect to Funfinder5's post, it's not the lower UHF channels that aren't used as much with the digital transition, it's the lower VHF channels, notably RF channels 2 thru 6, although some still are used such as WRGB ch. 6 in Albany, NY. The upper VHF range is also still used in many areas (RF channels 7 thru 13). So, VHF still does exist.
The UHF range (rf channels 14 thru 59) is used by approximately 80% of US TV broadcast stations now after the digital transition. Winegard came out with the UHF add on for their traditional batwing (VHF) antenna as more stations migrated to the UHF range after the transition. UHF always existed, it's just more stations have migrated to UHF after the digital transition. If the antenna on the unit you're looking at doesn't have the short 6 element add on to the original batwing which was designed primarily for VHF, but still worked to some degree on UHF, it can easily and cheaply be added. The add on will improve UHF channel reception while not compromising VHF performance which still is found in some areas of the country. There are still many RVers that use the batwing in it's original configuration and receive UHF channels.
Funfinder5 was correct though, there technically is no "digital" antenna.
VHF = Very High Frequency
VHF Lo = RF channels 2 thru 6
VHF Hi = RF channels 7 thru 13
UHF = Ultra High Frequency - RF channels 14 thru 59 (used to be 83, then 69, but now 59)
The higher the channel (frequency) the shorter the wavelength thus shorter elements on the antenna. The UHF wavelengths are shorter than VHF, thus the shorter element add on that Winegard came out with.