see this video for a live demo on how this system works
see how this system works

Amazon Reviews

This listing is for a brand new & factory sealed shark shkMBT88I Motorcycle Bluetooth Multi Interphone headset system. There are 2 headsets included in this system for 2 riders. This is perfect for motorcycle riders, clubs, and skiers.

This is a very high end system as it allows 3 riders to connect to each other at a time (of course you will have to buy another system to get to 3). The range that the 2 riders can connect to is a unheard of 1640 feet (500 meters). This system is fully weather protected. We have limited stock. There is a 2 year warranty on this item from us.
Description:

• Wireless hands free communication for motorcyclist
• It can pair "rider to rider" or "rider to pillion".
• It can pair 3 interphones at a time, and easily switch to any 2 of them.
• Works with any Bluetooth equipped mobile phone or MP3 Stereo music
• 500 meters Intercom range for drivers and passengers
• Up to 120km/h speed
• Up to 7 hours talking time
• Auto receiving cellphone calls
• Fits any motorcycle helmet
• Fully weather protected
• Wind and noise compensating microphone with super-slim speaker.
• Safe driving while talking with friend
• Player stereo music from your mobile phone
• Can be used as a bluetooth heeadset and a wireless music headset while you not riding