Greetings Spencer, welcome to the Forum :welcome:
The Pass-through feature, is designed to allow Analog Signals to pass through an Analog to Digital Converter Box, without any processing to Digital.
A "By-Pass" for all general purposes.
At this point, there are very few instances which require this feature.
IF, you live near, and are trying to receive TV from either Canada or Mexico, then, this feature may be required. Also, there are some rare instances, where there is an Analog station still transmitting in the US.
If you would like some assistance, in determining if any Analog Stations exist in your location, please go to the following link...
TV Fool (then click on "Signal Analysis")
Fill out the information, including the Height of your Antenna, then, copy and paste the link to that report in you next post here. That link is found in bold type, in a paragraph just above the round Chart in the TVFool report.
Also, getting a "fresh" copy of this report, will inform you if there are any new Digital Stations transmitting in your area, and give us an idea of how well you may be able to receive them.
Have a good Day !
S.W.