From Amazon
Noctua NF-A14 iPPC-24V-2000 SP IP67 PWM, Heavy Duty Cooling Fan, 4-Pin, 2000 RPM, 24V Version (140mm, Black)
3DJake
Noctua industrialPPC Fan 24V NF-A14 - 2000 PWM IP67 SP
Conrad Electronic
Noctua Noctua NF-A14 industrialPPC-24V-2000 SP IP67 PWM - 140mm PC fan Black (W x H x D) 140 x 140 x 25 mm