F 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. F Philips 33109900, 1 bulb(s), 4000 K, 500 lm, IP20, White Philips 33109900. Product colour: White, Suitable location: Backyard, Courtyard, Terrace, Shape: Round. Number of bulbs: 1 bulb(s), Total power: 6 W, Colour temperature: 4000 K. Cable length: 0,2 m. Power source type: AC, Energy efficiency class: F, Input voltage: 220 - 240 V. Width: 80 mm, Depth: 80 mm, Height: 55 mm