The 300 LPD ETC GLC Solar Water Heater is designed for larger families, guest houses, and small businesses that go through a higher volume of hot water each day. Twenty-four evacuated tubes deliver a substantially larger heat-collection area, and the reinforced Glass-Lined Coated tank is built to handle that increased daily cycling without losing efficiency over time. It carries the same 10-year tank warranty as the rest of the range, so you get commercial-grade reliability sized for a bigger household.