Even light bulbs have an energy rating, and this one is G-rated. On this light bulb you'll find a GX24q-4 socket.
From ManoMano
Greenice - osram/dulux GX24q 4 Traditional Light Bulb 42W 3050Lm 3000K Dimmable
LED Bulbs
Osram Dulux 42W PL-T/E Plus 4PIN Warm White - 425641
Big on Electricals
Osram Dulux 42W PL-T/E Plus 4PIN Warm White - 425641