BBB Japanese made liter-sized aluminum bottle cage for road and touring bikes.

 
The BBB FuelTank XL (BBC-15) is an extra-large aluminum bike bottle cage designed to securely hold large PET bottles, liter-sized containers, and flasks up to 1.5 liters. It features an adjustable clamping mechanism and a sturdy T-shape design.

I think these were discontinued and very hard to find these days.

Thanks for looking!