From the release:
Modular Kit: Dungeon is a printable dungeon tileset compatible with any RPG/Dungeon-Crawl game. It can be used as a standalone set, or combined with any same-scale tileset.
Modular Kit: Dungeon comprises 40 different tiles that can be printed multiple times and arranged in limitless combinations.
A set of 300dpi full size png files, for poster printing or VTT.
A page of dungeon accessories, such as pits, trapdoors and bone piles.
This set is compatible with the 2.5D crafting system, a crafting technique for making dungeon tiles more than 2D but not quite 3D. The 2.5D system was created by DM Scotty (Google his forum for tips)