@cindieku: "The Mico faucet I want is expensive on most sites, however this vendor has, what I can only assume, a copy of the faucet at a dramatically lower price."

I looked at that site - they don't list the manufacturer of anything they sell.

It's no doubt a copy. For all the time and trouble it takes in install a faucet, and the frustration if the knock-off doesn't work right, is it worth it?

I checked the domain registration for the site and this is what I came up with:

FaucetSuperDeal.com
7631 broadway street
LOWELL, Massachusetts 01854
United States
9782331433

I was actually surprised to see a US domain registration. I would call the number provided and also check them out with the Massachusetts Secretary of State and BBB.

But I agree that with products like this, where there is a significant risk potential for wasted professional labor and delay time, you are likely better served by a product provided by a reputable source.