Hello, everyone. I would like to bleed the radiator shown in the picture links below(I apologize about the camera quality):

http://img716.imageshack.us/img716/4848/imag0082pg.jpg

http://img94.imageshack.us/img94/9950/imag0084ri.jpg

http://img526.imageshack.us/img526/4078/imag0083k.jpg

I have bled other radiators in my house, but none of them are like the ones show in the photos. To be on the safe side, have any of you seen this? If so, do I simply turn the "key" above it, or does this radiator have to be bled another way? (If it is a "key", that is. And as a side note, the "key" was already there.)

Thanks!