Amazon.com: Noctua NA-VC1, 24V to 12V Step-Down Voltage Converter (Buck Converter) for Running 12V PC Fans in 24V Applications (3D Printers, etc.) : Electronics
Amazon.com: Noctua NF-A14 iPPC-24V-2000 Q100 IP67 PWM, Heavy Duty Cooling Fan, 4-Pin, 2000 RPM, 24V Version (140mm, Black) : Electronics
Computex 2015: Noctua -
Noctua NF-F12 iPPC-24V-3000 SP IP67 PWM, Heavy Duty Cooling Fan, 4-Pin, 3000 RPM, 24V Version (120mm, Black) Case Fans - Newegg.com
Noctua 24-Volt Fans and Chromax Review - Overclockers
Noctua 24-Volt Fans and Chromax Review - Overclockers
24V Alternative to 12V Noctua Hotend Fan (more in comments) : r/ender3
Noctua NF-F12 iPPC-24V-3000 SP IP67 PWM, Heavy Duty Cooling Fan, 4-Pin, 3000 R | eBay
Noctua NF-F12 & NF-A14 Industrial PPC Fan Review - Overclockers Club
Noctua 24-Volt Fans and Chromax Review - Overclockers