4-Pin Molex to 3-Pin Fan Adapter Cable (CAB177) ModMyMods.com - PC Watercooling Parts and Accessories
Amazon.com: OPSFALCON 2 Pack 4-Pin Molex (Actual 2-Pin) to 2 x 3 Pin / 4 Pin PMW 12V PC Case Fan Power Adapter Cable, 3-Pin or 4-Pin (PWM Connector) to Molex Computer
1.25mm Pitch 3-pin Cable Matching Pair - 40cm long [Molex PicoBlade Compatible] : ID 4721 : $0.95 : Adafruit Industries, Unique & fun DIY electronics and kits
4 Pin Molex Connector Male to Standard 3 Pin Fan Connector Male - MODDIY