That’s just a TV screen showing the output from the DVR, which had pass-thrus from all capture cards running to it. Kind of redundant and not real necessary but it’s easier to watch gates on the TV than the laptop w/ software, and the used DVR on eBay was like $25.
For wireless HDMI transmitters, these cameras work great, but you do need to get a 50-100mm lens.
I ran half wired/half wireless and for the wired ones I used some old Bosch IP security cameras with PoE (power over Ethernet) converters which sends power + analog signal over a single Ethernet cable.
… but that was all a lot of hassle and I’d probably just go 100% wireless going forward.
https://www.amazon.com/gp/aw/d/B07D4MNXVM?psc=1&ref=ppx_pop_mob_b_asin_title