Confused as to what this switch is?

Hi all, first time on here so please be kind to me. 
I have recently acquired Warwick duo and I don't know what a particular switch is for!

Any help will be good.
In advance i thank thee.
Ps, how do i attach a photo??.

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Plenty of Warwick Duo owners here (including me , Marquis version Sussex) so you could always describe its position and maybe we can help without photo.

You have got me intrigued now.

I'm also a Warwick Duo owner and want to know what that switch is for.  

Hi. Its on the front panel of the seating on the off side, it is directly in line with the trama heater!!

I had a 2013 Duo and was led to understand it was for the heat blankets on the waste and fresh water tanks.

I have a switch on the inside of that panel which is a mains electric switch for the Truma Combi. As its on the inside it never gets turned off.  I don't have one on the front. I only have a 3 pin mains socket there.
If you lift the seat can you see where the wiring from it goes?
I don't have tank heaters, mine is 2010.

Thanks for the reply, i will look see this evening.