Let me just state this upfront: if you are a publisher that does anything with fantasy, you are going to want this. With over 270 maps included, you're going to find something of use within. If you do 1e D&D style adventures, you're going to want to dungeon maps. If you detail locations, you're going to want the city maps. Even if you only use 1/10th of the maps within, that's is still 27 maps for $20, less than a dollar a map.
Just about all of these are in black and white. A few are in color. Pixel dimensions range from the 1000's x 2000's for some that are only a few rooms to the majority in the 2000's x 3000's and a few in the 3000's x 4000's. The largest I found so far is 12,600 x 9,226 (or 42 x 30.75 inches at 300 dpi)!
As stated in the product description, the license states "You are free to use, edit, modify, fold, manipulate, mutilate and mashup these maps as you please for personal or commercial works."
If you haven't subscribed to Dyson's Patreon where these maps come from, just get yourself this bundle. You won't regret it.