Review on 💻 12-inch PWM Fan Splitter Cable - TeamProfitcom Braided Y Splitter Adapter for Computer CPU Fans - PC 4 Pin Fan Extension Power Cable - 1 to 4 Converter by Mood Neboet

They work really great. As mentioned, only one connector has an RPM sensor cable. This prevents system confusion when attempting to read the fan speed. If each connector on the splitter had a speed sensor cable, the system would get multiple speed readings on the same mobile fan connector. This can confuse the system and cause problems. This is well designed and to work properly make sure you connect a fan to the RPM sensor head.