Nauta flexible diesel fuel tank
. 37 gallon capacity (advertised). Never was able to get more than 32 in.
Made of neoprene nitrile. 27"x46"
1 1/2" fill, 1/2" vent and feed line. All the fittings needed for a stand alone tank are included.
Tank alone sells for around $450 when new.
It was filled about eight times, and was never left in the sun for long periods of time.
PM me for more info.
Here is a link to the same model:
Bladder Tank - Flexible Nitrile for Diesel/Waste - 37 Gallon - Bladders & Tanks - Plumbing & Sanitation - Downwind Marine