Watercool Unveils Heatkiller Multitop X2 and X3 DDC Pumps and Expansion Top | TechPowerUp
 
The new HEATKILLER Multitop series for Lowara/Laing DDC pumps features a unique modular design and expandability. Each top is manufactured from a solid, 30 mm thick acetal block while the internal structure has been optimized for head and flow capacity. The series includes a SINGLETOP, a MULTITOP X2 as well as MULTITOP X3 and an EXPANSION-TOP. The SINGLETOP is designed to operate one DDC pump and, unlike the MULTITOPS, cannot be expanded.

The expandable MULTITOP X2 and X3 are designed to operate two respectively three DDC pumps in series, thereby significantly increasing the delivery head. For the MULTITOP X3, an EXPANSION TOP serves as connection between input and output. An expansion with additional EXPANSION TOPs is easily possible with both the MULTITOP X3 and X2, theoretically allowing infinite scaling.
 
A complex manufacturing process allows Watercool to mill the positioning attachments from a single block. This ensures less vibration at the transition to the pump and thereby also contributes towards a quieter operation. It also greatly simplifies the installation process.

Originally, the MULTITOP series was developed for industrial use. In addition to high performance, the focus here lies on maximum reliability.
 
The engineering looks very good in my opinion. Sadly I wasn't able to find prices for these.