Your light bulb would be the box labeled 6(2) A if I'm not mistaken. Though we would need some more information on how this is supposed to trigger. It looks like there is a secondary option, but is that for cooling, or is that a second heater?
Also, you have the wires there, do you know what each goes to on the other end.
I'm going to assume that this thermostat is only for heating and that it will close the switch/relay between 2 and 3/4 when temperature drops below what is selected on the dial. I am also going to assume that the wires you have showing there are for a three pronged, polarized plug and that green goes to the ground (round prong), purple goes to hot (small prong) and blue goes to neutral (large prong).
In that case, you would connect green to the first position, which looks like it has the ground symbol already, just no screw. In my opinion, that is a bit of a red flag. Purple connects to#2. Blue would connect to one end of your lightbulb and#6. The other end of your lightbulb would need to connect to both#3 and#5.
I am a little bit concerned that this thing says 230V though. Where did you get this thing and what power source are you plugging it into? Also, Why is terminal #1 between #4 and #5? That's ridiculous.
Why didn't you just pick up an STC-1000, looks like it would have more functionality.
