Features: 1) Pressured water tank for solar collector / solar panel 2) Capacity: 100L, 150L, 200L, 250L, 300L 3) Water tank inner diameter: 400mm, 400mm, 520mm, 520mm, 520mm 4) Water tank outer diameter: 480mm, 480mm, 610mm, 610mm, 610mm 5) Thickness of inner tank: 2mm, 2mm, 3mm, 3mm, 3mm 6) Thickness of insulating layer: 40mm, 40mm, 45mm, 45mm, 45mm 7) Material of insulating layer: polyurethane 8) Size of water pipe: G1/2\'\'\'\' 9) Power of auxiliary heating: 1,500W