Hi, I'm Mike, a Yank living in S. Korea. My Korean brother in law is a manufacturer of said callus removers, a pretty decent product as it sells well in Japan, and we're looking to get into the NZ market. Me personally, I've only recently joined up with his company as he doesn't have a native English speaker readily available. He has a few distributors who have English speakers of course, but now that I'm here, we can cut out the middle man (Korean distributors) and sell direct.
Our main business is actually 'Skin Meso Rollers', or DTS Rollers. They of course are a more difficult product to deal with as regulations vary by nation on micro needling.
Benefits: Buy directly from the factory.
Deal with a native speaker in your relative time zone.
OEM available, but MOQ is higher.
More info at dtsrollers.com