I saw this and thought about using it for a school rocket project. It's a good size, the letters are really big and clear. Batteries are included so you get up and running right away. I have a different message board easily programmed via USB but for the price, this badge is completely self-contained. Okay, with only three buttons to program the messages (five separate texts), it's a bit fiddly. The buttons are not the most comfortable and your finger tips can get sore on a long message. Editing while programming the message is rudimentary but effective. The scroll speeds are fine but I'd like to have had a slower speed than '1' as it is sometimes a little too fast. The display can be rightened for strong sunlight or muted for indoors.
The lanyard and pouch is a great idea. No need to worry about pin holes in your clothes. If there is one issue, it's editing a saved message - you can't. When you select INPUT for a message, it wipes that message ready for new input. With between 256 and 512 characters in the messages, it is labour intensive to re-enter a long message.
Still, it's a fascinating piece of kit and fantastic value for money. I'll be back to buy more of these when we select our teams for the next competition!