Anywhere to buy a wrist or arm mounted wireless keyboard?

I need a wireless keyboard to control my computer, but it needs to be mounted on my wrist like they have in the military. Anywhere you can buy these? I can find ONE wired one, but they only sell to the US, and another is much too expensive because it's the real deal.

Will I just have to buy a tiny bluetooth one and adapt it into some sort of wrist form factor or are these available anywhere?