It is an LCD (Liquid Crystal Display) that is embedded as part of a brochure. It can have a hard cover or a soft cover, and they can be any of a number of sizes, from the size of a video business card to a full size page.
The videos on the brochure can be your own (you can upload them yourself) and you can mass duplicate them, or upload a different video for each brochure. For instance, you can purchase 10 brochures and record a custom message for 10 clients and send one to each. Or you can have one video and save the same video to all 10 brochures.
The maximum length of the video varies depending on what you are willing to spend.
Think about all the money you spend on marketing. How much are brochures? How about business cards? Flyers? SEO? Website? Videos? You may find that your marketing budget can be optimized by combining some of those elements in one. You probably have a marketing video created. Even if not, you can create a simple one on your iPhone or Android device. And we know how valuable a video can be as far as succinctly proclaiming your message and even customizing it to your intended audience. You can now literally mail a video to people, or hand it out as a marketing device.