Desmond Photographic Distributors is an American company based in Texas. I have a couple of their clamps and they are excellent quality. I suspect they are made in China because the prices are so low, but they seem to be made to a higher spec than the usual Chinese stuff.
S.C.V Photo has reviewed a lot of their products:
Interesting. I noticed that they have a link to Sunwayfoto on the site, so for sure they have connections to China. Thanks for the info.