There are mainly 3 types of systems on the market. The first is a Live Guide System where a live person can speak directly to a whole group through a wireless system. Orpheo OTG systems can work with over 100 people at a time at a distance of nearly 300 feet. The second system is a Audio Guide system. This system stores pre-recorded mp3 files in its memory which can be played by pushing a number on the device or can be triggered automatically with IR beacons. The orpheo Mikro LX system can hold hundreds of hours of tours on its devices. The last system is a Multimedia Guide which allows apps to be employed. These devices can run on buttons, GPS coordinates , Bluetooth and IR technology. The Orpheo devices even run without wifi.