4" 4-Pin (M) to 3-Pin (F) Adapter for Case Fan. Are you looking for high quality fan adapters to use in your system? We sell Kingwin ML 01 4pin to 3pin Power Adapter so you can connect your fans to your system without a hitch. Its 4 inch length gives some opportunity for routing and managing the cables. 4 4Pin M to 3Pin F Adapter for Case Fan. 4" 4-Pin (M) to 3-Pin (F) Adapter for Case Fan.