Cables To Go offers a wide variety of personal computer internal power cables for your case cooling requirements. Whether you have a 4-pin or a 3-pin fan, Cables To Go has the cable you need. Add, split, or extend your internal 3-pin power products with genuine Cables To Go internal 3-pin power cables. This 3-pin fan to 4-pin pass-through power adapter cable converts 3-pin fan connector to standard 4-pin power connector with power pass-through. It is designed for CPU and case fans.