gotcha, thanks. mind if I ask you two more questions? With something like this kit - https://www.amazon.com/Reolink-Surveillance-5-Megapixel-Security-RLK8-410B4-5MP/dp/B016UCNP3A?crid=1D6PWD41XJY2W&keywords=security+camera+poe+5mp&qid=1539137191&sprefix=security+camera+poe+%2Caps%2C223&sr=8-4&ref=sr_1_4

if something went wrong with a single camera can you replace it with any other individually sold POE camera like say https://www.amazon.com/Security-Megapixels-2592x1944-Waterproof-Detection/dp/B07BNGWZVR?crid=1D6PWD41XJY2W&keywords=security+camera+poe+5mp&qid=1539137191&sprefix=security+camera+poe+%2Caps%2C223&sr=8-7&ref=sr_1_7 ?

and if I were to buy just 2 or 3 of the second linked individual cameras, would they work with https://www.amazon.com/TIGERSECU-4-Channel-Security-Recording-Included/dp/B076H2DHBS?keywords=security%2Bcamera%2Bdvr&qid=1539137634&sr=8-8&ref=sr_1_8&th=1 ?

thanks