I just bought and installed a Cardo ScalaRider G4 Headset for my Scorpion helmet and am quite satisfied upon first use. It installed easly with the included hex wrench on the right side of the modular helmut, with the earphones routed underneath the edge and then under the helmet padding. They velcroed to the existing lining without using the included velcro-backed tape. I interfaced it intitially to my iPhone, testing both the iPod and phone features succesfully. I then interfaced it to a modified Yeasu VX8DR amateur transceiver with AM/FM stereo radio with no problems whatsoever. The built-in FM radio worked well on the intial test, but is a bit cumbersome to tune new radio stations while in motion. I do use heavy guantlet-style leather gloves from Jammin' Leather and had no issues with activating and deactivating while driving. I also use plastic earplugs from EAR and had more than ample volume at high speed. So I now have cellphone, mp3, AM/FM stereo, shortwave, ham/frs transceiver, military/police/air scanning capabilities. It will also interface with most bluetooth enabled GPSs, but I have not tested mine just yet. I found it on eBay new for $185.00 shipped.