Please keep in mind that it may be illegal to intercept a conversation without all parties consent. Even if the possibility exists of it occurring by accident. If in doubt don't use any device that records or transmits voice communications. Such devices include tape recorders, camcorders, baby monitors, etc. Just make sure you conform to all laws and regulations.
All kits come complete with a pre- printed circuit board, components, and full instructions.
The kits are easy to assemble with a few basic tools and a soldering iron.