What does the fuse in the green holder do, as seen in this photo.  It located behind the dash on the drivers side, just above the pedal box. 

 

Also what is the correct size fuse for this? 

 

 

If it's in the position in the picture it's the 30 amp supply for the electric seats, if it's at the left end of the rail then it's the 30 amp supply for the electric windows

Thanks, I don't have electric seats, so must be for the windows.