Question about fan splitter

[Henry19941994]

So recently I bought a fan splitter from Noctua, however, one of the connector was missing one pin, should I still use it? 

The splitter I got was like the middle one, only had 3 pins on it. Can I still use it? And if it's how it is, why are there only 3 pins instead of 4 pins?

[MkaiL]

The third pin is missing because your motherboard can only read the rpm signal of one fan and not both (on a single header). That's normal and it's perfectly fine to use. 

[Henry19941994]

2 minutes ago, MkaiL said:

The third pin is missing because your motherboard can only read the rpm signal of one fan and not both (on a single header). That's normal and it's perfectly fine to use. 

Thank you so much