Here is a paragraph from the Tom's hardware "Wraith" review.
"Once the Wraith's cover is removed, we find an old friend: the QFR0912H by Delta. This model has a 92mm fan that's 25.4mm thick and runs at up to 3200 RPM with 5 to 13V, consuming a maximum of 2.64W. At its peak voltage of 12V, we measured the RPM at exactly 3100. This particular fan costs less than $5 if purchased in large quantities, which doesn't exactly make it an expensive offering. However, it's not cheap either, and is most certainly a step up from the fan that was included on AMD's previous stock CPU cooler."
This sounds about right. The cooler plugs into the fan headers on the motherboard. So, 3v, 5v and 12v are available to it. And the voltage will very with the fan speed. The older Wraith cooler and the newer cooler probably use the same fan.