This is module 1x3x5 and 1x3x6 of gridfinity storage system.
Material: PLA
Nozzle: 0.4
Supports: Not required
Two heights, 6U - because that is the height I usually use, 5U - for saving some filament.
If you do not know the gridfinity, then:
Creator of Gridfinity - Zack Freedman
The author hasn't provided the model origin yet.