Water & gas combination unit ,Fitted with over heating and pressure safeguard Suitable for both summer and winter Mains power not required Electrical requirement: DC3V, Automatic electric ignition powered by two (2) size ‘D’ batteries (batteries not included); No electrical hook up; No standing pilot; Description: 1. High efficient energy saving : the heater exchanger and main burner adopt mostly advanced energy-saving and combustion technology to decrease gas consumption and burning noise. 2. Low water-pressured startup : the water control linkage valve makes the heater start up under low water pressure and shortage areas and those living in high stairs. 3. Manifold auto protection : for the sake of your safety 4. Ion flame inspection : to automatically shut down gas power under unexpected flameout. 5. Over water pressure protection function : to automatically decrease pressure under excessive high water pressure. 6. Controller design : both cold water and warm water can be properly controlled 7. Magnificent thin-shaped appearance : it is designed by modern fashionable line shape.