This light bulb has an A energy rating. The socket on this bulb is a so-called GR10q socket.
From Amazon
Osram CFL Square 38 W/835 4-PIN, GR10, W, 835 Warmton
LED Bulbs
Osram 38w CFL square 2D Bulb GR10Q Cool White 817026
Big on Electricals
Osram 38w CFL square 2D Bulb GR10Q Cool White 817026