The energy efficiency class of this bulb is G. This particular model has a so-called 2G11 socket, so make doubly sure that it will fit.
From Amazon
Dulux L Warm Light Bulb 18 W Eco Warm White 2G11
LED Bulbs
Osram Dulux 18W PL-L 2G11 Warm White - 010731
Big on Electricals
Osram Dulux 18W PL-L 2G11 Warm White - 010731