These 27cm extension cables allow you more choice in where you want to position your PWM or standard 3 pin fans inside your case. The wires are 27cm sleeved in black braiding with a 4pin female connector at 1 end and splits to 2 4pin male connectors at the other. Please your motherboard fan header is capable of the additional electrical load before purchasing any of these. Please note - all the connectors are 4 pin connectors, but one of the connectors only has 3 wires. The reason for this is that the sensor wire is not used on this connector as if both fans were sending back information to the it would not be to understand the information as both lots of information would be back through the single connector. What happens is the fan with all 4 wires tells the the information, and then the controls the speed of both fans. These do also have a cut out so you can use 3 pin fans instead of 4 pin if you wish. size:Line length 27cm Material:PVC colour:black Package Contents: 20 x Fan Extension Adapter Cable Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.