Summary: do not question this too much. If you have a slot for a 140, stab one of these bad boys in there and reap the quiet rewards and air moving goodness
Pros: I will tell you what, these fans are absolutely amazing. Have 3 in my case and you can not hear a whisper from any of them all while they move a copious amount of air. these inspired me so much I also replaced the 120 that is on my 212 and the one on my case exhaust. These have made me a huge fan...
Summary: The wiring, while sturdy, is a tad long. Keep in mind you may have to find some way to tuck it away or around other components. Keep in mind it is a 3-pin fan, so the speed can not be adjusted.
Pros: Silent, compared to 4-pin fans running at higher speeds in the same system. Higher airflow and quieter performance compared to the stock rear exhaust fan it has replaced.