Fan Controller card

[Ekim]

I was looking through the posts the other day and came across reference to a hardware or cooling site that offered a small card(2X2?) with or without their fan that plugged inbetween the mobo and the cpu cooling fan. This card controlled the fan speed. You just tell it what temp you want the cpu and it worked the fan faster or slower to achieve this temp. I can't find the site again. Has anyone seen this? Help me out please.