Confused with case fans

[Atls]

Hi. I got new fans, but I'm confused with the cables that come with them:

Fan Cables

So I see that in the small bracket I attach the fan cable itself, and on one of the larger brackets I attach the 4-pin power from the PSU itself. But what's the other adapter for? Why are there two?

 

[KH85]

Its so you dont use up a Molex connector on just a fan..... I.E you can run another device of it like a HDD or a DVDRW.....

 

[Atls]

Nice! Thanks for clearing that up.