EKWB has built a new version of its EK-DCP 4.0 water pump adding PWM compatibility. The water pump is built to be used in liquid cooling loops and runs off a 12 V source. A motherboard header is only present to control the PWM signals and return an RPM readout.
The pump is powerful enough to pump through about 800 L of water per hour, though of course when the system is under lower loads, it doesn't need to pump nearly as much fluid in order to provide sufficient cooling. That's where the PWM support comes in handy, as you'll be able to slow down the pump to a more reasonable speed for idle operation in order to reduce pump noise when not necessary. Threading is present with support for the standard G1/4" fittings. EKWB has rated the pump to be able to support maximum fluid temperatures of up to 60 C, and the unit is said to last for about 50,000 hours at 25 C.
Pricing is set at $66.33 with immediate availability directly from EKWB.