What is this rear seating system called

[Necessary Jago]

Apologies but I've searched for a long while and cannot find information about this system in the back of a kombi. I'm looking to replace the seats with some that fold, but would appreciate if someone could at least tell me what it is I have now!
Many thanks

 

[paddy26]

Unwin rail. Its common in mobility conversions.

 

[Necessary Jago]

Unwin rail. Its common in mobility conversions.

Thanks Paddy. Perfect

 

[AK06FR]

L-Track i another name for it. I have it in my van for the rear seats.

My seats and bases came from here:-

VanX - Schnierle EN