Animal Rights

Today they showed this new artificial arm or leg on the news. Apparently it's very revolutionary.
I'm sure a lot of people will benefit from it.
But it was tested on this monkey. The animal was pinned down in this machine and could not move its head. The monkey didn't really seem to enjoy it!
I guess, I wouldn't either.
Is it ethical to use animals for testing products?
Is it ok if we benefit from it, is it not ok if it is just to test a new product that will be mass produced for consumption?
It's a thin line to walk on and I guess most people don't really care as long they don't have to look at it.
It's hard to be a Monkey now a days!