I already have one of these drains in a St. Thomas counter-top vessel sink in my powder room. They are standard size drains, and they work EXACTLY like the one Jason has in his bathtub. I want another one because I'm installing a custom-made vessel sink into an antique dresser in my master bath. It's much easer to deal with this type of pop-up drain with a vessel situation because the faucet (in my case) is sitting on the surface of the dresser, which is on level with the drain (the vessel itself is about 7" above the counter surface). Because the faucet and the drain are on the same level, the standard pop-up drain using a rod is more difficult to install because the drain extension the rod goes into is too high... which means you start customizing the plumbing, and we all know what a pain in the bahootie that is! Thanks for your response. I will try contacting St. Thomas directly.