We've just had delivery of a new bluetooth system - Sena SMH5, it sounds very very similar to the Scala Rider but retails at £90 for a single unit and £170 for a dual kit. Like the Scala Rider, they are very easy to install, fixing directly to the side of the helmet with either a sticky pad or a clamp (the unit can easily be unclipped and removed for charging). Stereo ultra-slim speakers, directional mike and easy to pair up. I had the unit fitted to the helmet and paired to my phone in just a couple of minutes. You can pair it to up to 3 other devices, but I think, like the Scala, you can only talk/listen to one device at a time, which is annoying if you want to hear listen to your satnav and talk to your mate/missus. On the plus side though, the sound quality was superb and the range isn't bad either ~100m in heavy traffic and a stated 500m on the open road with direct line of sight. It's a good quality headset and I'd buy one for myself to connect to my phone, which I would use for music, satnav and incoming calls. But it's not for having a ride out with your mates and chatting with them (unless you only have one mate).