... solar energy collector technical date:1) Model no.: JHC-58/18-20 2) Quantity of tubes: 10,12, 15, 18 ... , 20, 24, 25, 30, 36.3) Seperately packing?: Yes ... length of tube : 1800mm6) Total diameter of tube: 47/58/65 mm7) Gross absorb area (m²): 3.14/3. ... 1) Hail resistance: ≤25mm2) Diameter of tube (mm): 47/58/65mm3) Glass quality: Borosilicate glass 3.34) Thickness (mm): 1 ...