... Model Number: 20,25,47,58 mm Style: silica gel circ silica circle for solar water heaterProducts feature1,made of ... good quality and a long service life. Product attributesNamesilica gel circleFull specifications20,25,32,47,58,70mmProduct size20,25,47 ... changed by your detailed information. Technical controlMachine High-precision double-pump full automatic high speed front mould-open hydraulic pressure ...