Amazon.com: PWM GPU Fan Adapter Cable, Mainboard Standard 4-pin to GPU Mini 4pin Extension Power Cable, Graphics Card Cooling Fan Connector : Electronics
IDE Molex 4 Pin Socket Cable - 30cm long : ID 5365 : $0.95 : Adafruit Industries, Unique & fun DIY electronics and kits
RAIDMAX Molex 4-Pin Male To SATA 2 15-Pin Female Power Adapter Cable (4 PACK) 854190001190 | eBay
PC power supply cables and connectors
4 pin fan plugged in using a modified Berg connector : r/techsupportmacgyver
3 Pin Y Splitter All Black Ribbon – Coolerguys
1pc 5.25" 4 Pin Molex To 2 x 3.5" Floppy Drive FDD Power Splitter Adapter Cable | eBay
4x 4 Pin to 6 Pin PCI-Express Video Card Power Converter Adapter Cable Replacement Wire Line for Molex - Walmart.com
PCIe 5.0 High-Power Connector For Next-Gen Graphics Cards To Deliver Up To 600W To GPUs