What is the difference between the Tufftalk M and the Tufftalk or Tufftalk Lite?

The Tufftalk M features Sena's Mesh 2.0 intercom technology which makes communicating in groups easier than the Tufftalk or Tufftalk Lite. With Mesh 2.0, the Tufftalk M does not need to be paired to other members of the group like with the Bluetooth Intercom feature on the Tufftalk and Tufftalk Lite. In addition, the Tufftalk and Tufftalk Lite only allow up to 4 people to communicate with each other while the Tufftalk M allows a virtually limitless amount of people to talk to each other within 1.1 km (0.7 miles) in open terrain. In open terrain, the Mesh can be extended up to 4.4 km (2.8 miles) between a minimum of 6 users.