CPU fan - 3 or 4 pin header?

(I did think about posting this in the 'Chassis' topic, but it seems a bit quiet in there!)

Hiya guys, just putting a new system together using a Thermaltake Frio CPU cooler with a 3 pin fan. My motherboard though (an Asus P8Z68-V Pro) has a 4 pin PWR_FAN header.

1. Which of the 4 pins of the header do I use for now, to connect my 3 pin cooler fan too?
2. Can anyone provide me with a link too a 4 pin-3 pin convertor or splitter?

TIA

You will only be able to fit your 3-pin into one position on the 4-pin socket, due to the guiding tab. But 3-pin is designed to fit on the 4-pin without an adaptor.

3-pin fans will plug into 4 pin connectors.

Connect it to the CPU_FAN (what it's normally labeled)

Doh! Thanks fellas!