B means that the product is rated in its category in terms of energy efficiency. The Energy Labeling system is based on EU Regulation 2017/1369/EU. B A+ to F Ariston VLS WIFI 100 EU, Tank (water storage), Horizontal/Vertical, 1500 W, 100 L, Solo boiler system, Indoor Ariston VLS WIFI 100 EU. Placement supported: Horizontal/Vertical, Type: Tank (water storage), Boiler system: Solo boiler system. Maximum power: 1500 W, Water flow (40 °C): 125 l/min, Maximum operating pressure: 8 bar. Display type: LCD, Load profile: M. Energy efficiency class: B, AC input voltage: 230 V, Annual energy consumption: 1296 kWh. Width: 19.9" (506 mm), Depth: 10.8" (275 mm), Height: 49.3" (1251 mm)