AQUAH INDOOR WHOLE HOUSE LIQUID PROPANE GAS INDOOR TANKLESS WATER HEATER 6 L / 1.6 GPM AQUAH liquide propane gas tankless water heater, 1.6 gal (6 L)/min or 96 gal/hr; Automatic electrical pulse ignition with no standing pilot, operated by 2 D Batteries; 85% thermal efficiency, 12,000 Watt / 40,900 Btu/h thermal input 45 dgrees temperature rise at the flow rate of 1.6 gllons per minute (GPM) Free 1/2" BSP (Metric) to 1/2" NPT adapters for gas/water fittings ($45 value).