D means that the product is rated in its category in terms of energy efficiency. The Energy Labeling system is based on EU Directive 2010/30/EU. D Siemens LU63LCC40, 350 m³/h, Ducted/Recirculating, E, E, C, 72 dB Siemens LU63LCC40. Maximum extraction power: 350 m³/h, Type of extraction: Ducted/Recirculating, Fluid dynamic efficiency class: E. Type: Built-under, Product color: Brown, Control type: Buttons. Grease filter type: Aluminum. Bulb power: 4 W, Number of bulbs: 2 bulb(s), Bulb type: LED. Energy efficiency class: D, Annual energy consumption: 93.3 kWh, Energy efficiency scale: A+ to F