I use 2 Sena SMH10 between 3 helmets. for my helmet i bought the headphones adapter which includes the microphone. This allows me to use my own headphones. Then for the other 2 helmets, i use the microphone and speakers that come with set. This allows you to velcro the speakers right next to your ears. My wife had no problem hearing me at highway speeds. I highly recommend the Sena, best money I've spent on helmet communication device. Plus it controls your bluetooth phone and if you have an Iphone, you can press the cell button once, wait for the tone and you will be able to issue commands to the phone (call john mobile or play playlist 1 etc).