Zalman FanMate -1 One Fan speed controller.
FAN MATE 1 is an adjustable fan speed connector for allowing you to control the speed of a fan to create an optimal cooling environment.
FAN MATE 1 Specifications
Dimensions (mm) 200(L) X 21(H) X 23(W)
Weight (g) 20
Output Voltage 5 ~ 11 V +-2%
Allowable Wattage 6W or lower
*Please check the allowed wattage of the CPU fan connector on the motherboard, as well as the rated wattage of the fan to be used.
*Zalman Tech. Co., Ltd. is not responsible for any damage to systems or CPUs caused by using the product outside of its specifications.
* Do not use FAN MATE 1 with a fan having a start up voltage of more than 5V. Please check the start up voltage in the specifications of the fan.

http://www.zalman.co.kr/usa/product/cnpsfanmate.htm