DN40 47mm Tri Clamp Heaters Electric Heating Elements AC220V/380V with BSP Thread for Solar Water Tank 3KW/6KW/9KW/12KWSpecifications:Product Name: Water Heater ElementTube Diameter: 8mmThread DIameter: DN40 (47mm)Voltage: 220V/380VTube Material: 201 stainless steelThread Material: CopperPower: 3KW/6K W/9 KW/12KWPackage Contents: According to what you choosePay attention: Power Allowance -10%~+5% 01/Notices:The warmers for water/liquid,cannot dry burning/SUS304 Stainless steel:Has a definite acid and alkali resistance,high density,polishing,no bubbles,no pinholes etc. ,its the manufacturing of each variety of heater ,bottom cover, positive materials and so on/Can you warmth the water within the well?There are complex chemical detail in effectively water, cant opt whatsgoing on with the steel tube do not recommend using.