This is a lamp from LEDVANCE which requires one bulb. This fluorescent fixture should be used indoors and recommended wattage for bulbs is maximum 16W.
Linear luminaire LED: for ceiling, G13, SUBMARINE© / 16 W, 220…240 V, Cool White, 4000 K, body material [calc.]: acrylonitrile butadiene styr, /, 1-pack
LEDVANCE SUBMARINE (EU) Wet room diffusor LED (monochrome) G13 16 W Cool white Grey