These are virtual maps meant to be used for Virtual Tabletops. They come from the adventure The Thief Kings Vault, but can easily be incorporated into whatever game you have the desire to use them for.
GM Overlay Layer maps with just the map keys. Those of you that use Roll20 will appreciate these very much.
Grid and Gridless versions of player maps
A Grid Alignment Template on each map.
Specifically the maps included are:
The Thief Kings Vault