The coolers are constructed from 42mm plumbing copper pipe, the cpu end is a 45mm by 45mm sheet of copper, the other end is a brass plate of the same dimensions. The pipes are 6mm (approx) od brass. Since the pictures were taken peltier devices bonded to 45mm square copper heat spreaders have been laminated between the processors and coolers. The water is circulated by a tiny OASE Aquarius 300i fountain pump, through a modified Ford Transit Heater Matrix and then through the coolers. (pump consumes just 4.5w).page2