Red Button Under Driver's Seat ??

[SamClarke_Films]

Hello!

I bought a second-hand 2011 T300 SWB back in December and wonder if anyone can help me to identify what this red button does, under the driver's seat?

It connects to two batteries under the seat and I was originally told by previous owner that it might be a split charge for the 2nd battery, but I really don't think it is, as there's no relay system fitted.
Since the video in the link below, I realised it's not even a leisure battery but simply two batteries for the van.

Video here: https://youtube.com/shorts/j-Db0ZgUVW8?feature=share

I tried to find it on the online user's manual, but it doesn't mention it.

Any help appreciated!

[Frag]

It’s for the drivers heated seat,the part of the switch that would have the picture on has fallen out….

Chances of heated seat still being fitted,or still working are slim anyway…

[SamClarke_Films]

Thank you!