Tor, Shadowsock, Latern, Psiphon,... They open socks proxy on localhost then transfer traffic to internet. They have a loopback connection.
Instead of: Browser -> VEthernet -> Tor -> Internet; then: Browser -> (Tor -> VEthernet; loopback) -> Internet.
So how to use VEthernet with them, and I dont know the command --product=yes it is for what.