The bulb can be lit for about 20 000 hours before it needs replacing. On this light bulb you'll find a G24q-1 socket.
From Amazon
Osram Dulux DE 13 Watt 840 4P G24q-1
LED Bulbs
Osram 13W Dulux DE 4 Pin Compact Fluorescent Cool White - OS017594
Big on Electricals
Osram 13W Dulux DE 4 Pin Compact Fluorescent Cool White - OS017594