The energy efficiency class of this bulb is G. On this light bulb you'll find a G23 socket.
From Amazon
Osram Low Energy Lighting 2 Pin Single Tube CFL 7w G23 Warm White 10000 Hours
LED Bulbs
Osram Dulux 7W PLS 2PIN Warm White - 4050300025735
Big on Electricals
Osram Dulux 7W PLS 2PIN Warm White - 4050300025735