This technology is so flooded with Chinese-manufactured POS products I have some pertinent advice:
If you don’t care about ending up with a piece of Chinese hardware that also has software written by Chinese developers, copying someone else’s work and inserting their own malicious code, and have dozens (if not hundreds) of hours of spare time on your hands to fully research your purchase, and don’t care about wasting $$ on hit/miss purchases you can’t return, then yes, go online and buy.
Otherwise, spend some better time and ask around for referrals for ‘security system professionals’ that can get you what you want and plan on paying good $$ for it.
yes, I am aware of all the crap coming from china.