Inner Tank: Stainless Steel SUS 304 or SUS 316, 1.2-1.5mm thick Outer Tank: Stainless Steel SUS 430, SUS 304, SUS 316 or Carbon Steel Painted Brackets: Stainless Steel SUS 430, SUS 304 or SUS 316 or Carbon Steel Painted (Type: Flat Roof Mounts, Pole-side Mounts, Pole-top Mounts) Water Inlet/Outlet, Electric Heating Element Installation: In the bottom of storage cylinder Technical Parameter C-D Series ModelApplicable Rage (Persons)Evacuated Tube SizeQuantity of Tubes (pcs)Heat Collector Area (m²)Storage Cylinder Capacity (Litres)C-20/1.5GD2-4Φ47x1500mm202.10150C-24/1.5GD3-5Φ47x1500mm242.52180C-12/1.8GD2-3Φ58x1800mm121.79110C-18/1.8GD3-5Φ58x1800mm182.60190C-22/1.8GD5-6Φ58x1800mm223.18230C-26/1.8GD5-7Φ58x1800mm263.76270