This is a booster pack for the Space Shuttle Edeavour. It consists of the Orange external tank and two Solid Rocket Boosters. The pack is attached to the Orbiter using the holes for a stand.
In the suffix of the files, there are color codes:
w-white
b-black
g-grey
gl-gold
(for the files with no suffix, it doesnt matter which color you use)
Video about the project: