... SRCC / CCC / CE /SOLARKEYMWRK / ISO9001-2000 Compact Copper Coil Solar Water Heater .We put quality as the first consideration , ... rubber ringHeat exchanger: 40m long, 12mm diameter, 1mm thickness copper pipeinlet,outlet:1/2' or 3/4' BSP maleStand: ... digital control displayFeature:The system consists of solar vacuum tube, water tank, assistant tank, copper coil, electrical right bracket (optional), ...