From the publisher:

This supplement features d20 statistics for 12 new ray guns, suitable for any modern or science fiction adventure. Three different models of the death ray are presented along with other classic concepts like heat rays and laser rifles. There are also several innovative ray guns in this collection including psychic blasters, phase guns for shooting extra-dimensional enemies, and rift guns, which cause deadly disruptions in the dimensional fabric of reality. Pulse guns can be used to neutralize machinery and the dreadful ion gun can inflict maximum suffering on living creatures.

This supplement also features three additional accessories for ray guns including amplifiers, which overcharge an energy weapon and increase its effects. Rules for crafting each of the ray guns along with a brief discussion of their frequency and intended roles are also covered in the first section of this supplement. 1948: Ray Guns also features 7 original images of the ray guns and 5 unique audio files, allowing you to hear these awesome weapons in action!

You get all this:

12 ray guns including death rays and pulse guns
Rules for crafting ray guns
Rules for amplifiers and external battery packs
7 images including one photo of a rift gun being field tested
5 audio WAV files, so you can listen to the ray guns when you use them!