This bundle includes the Alphacool VPP Apex Pump and ES 4u Reservoir with D5 Top. The Alphacool Apex VPP is a powerful pump that is compatible with the most common D5/VPP tops and reservoirs. The speed of the pump can be read out via the 4-pin fan connection and controlled via a PWM signal. The Apex VPP is powered via the SATA connection. Power supply Compared to Alphacool's ice pumps, the power is not supplied via a 4-pin Molex connector. Instead, the Apex VPP pump connects to the power supply using a SATA connector. Control The Apex VPP pump has a 4-pin fan connector that connects to the motherboard or to an external controller. The speed range of the pump can be controlled and read out via PWM. 2500-4500RPM The Alphacool ES 4u Reservoir with D5 top is a development for the Enterprise Solutions series. It has an integrated pump top for powerful D5 pumps. The combination of pump top and reservoir was designed to be mounted directly in the front of 4u servers. The positioning of the reservoir in the enclosure and the acrylic cover used to make maintenance and control of the water circuit much easier. The ES 4u Reservoir has a total of 3 inlets and one outlet. All connections use a G1/4" thread. 2 inputs are located on the acrylic cover in the front range. The reservoir can be perfectly filled or emptied via these inputs. The input and the output for integrating the reservoir into the water circuit are located on the back. The ES Reservoir is mounted in front of a 4u server rack. The acrylic cover allows visual control of the water cooling level. The G1/4" inlets in the cover allow easy filling, draining, and venting of the water circuit. 4x G1/4" internal thread.