47*1.2太陽(yáng)能真空管
47*1.2 solar vacuum tube
47 for the solar vacuum tube diameter is 47 mm, 1.2 for the solar vacuum tube length of 1.2m! The product can be said to be relatively old solar vacuum tube! Although this type of solar vacuum tube is no longer the mainstream market, but its performance in a small amount of melt water of solar water heater is very useful! And the price is very high!