They have a U.S. warehouse to ship orders from (only certain items denoted with an American flag symbol on the description) but they are a foreign owned company, yes. From the site:

"Our USA warehouse will increase in stock every week as we ship more products to the US & CA.
Please check back regularly for updates, or subscribe to our newsletter for updates."

And a searchable 94 pages of items available from their U.S. warehouse. The results of a "2.4 GHz" search here: https://www.hobbyking.com/hobbyking/store/us.asp?schUS=2.4+GHz