It does exactly what it says. Simple mechanical switch. I have it set up to connect a network card to 2 different networks, obviously one at a time. I've reached speeds up to 450, I don't think it puts any limit, I haven't tried it on LAN to see if it slows down gigabit but I don't think this would be the cause if something like that happens. It seems durable, and it's not even in the most friendly environment, it faces heat and dust.