It is a 140mm fan but it is not screwed in, it is just laying there. A 140mm can't actually be there screwed in, it was designed for a 120mm. I just have it there for the moment until I get the rest of my Corsair fans.
Edit: If you really wanted to you could create your own screw holes and make it fit, if you are comfortable with modding it in such a way. I am terrible with tools so I am not going to do it. xD