Given that Mako appears to be extracted in liquid form, FFVII Remake shows Mako cylinders taking after real-world natural gas tanks.
That object is a “Mako Cylinder” (or Mako Tank), a key item in the FFVII Remake system of Mako supply.
Square Enix dropped some new trivia about the world of Final Fantasy VII Remake on April 18, 2022.
Whereas the original Final Fantasy VII didn’t elaborate much on exactly what Mako energy is or how the Shinra Electric Power Company extracts it from the planet, FFVII Remake goes a bit deeper into Mako supply details.