The Sena SRL EXT-01 is a mesh communication system that has been designed for used with the Shoei NXR2 Helmet.SOUND BY Harman Kardon speakers and micDesigned specifically to fit the SHOEI NXR2Bluetooth 5Mesh Intercom 4-way Bluetooth IntercomDigital Assistant AccessAdvanced Noise Control The Sena SRL EXT-01 has been designed with sound at the forefront. It is installed with Harman Kardon speakers and microphone to ensure the most clear experience possible. It comes with Bluetooth 5 installed and is a mesh intercom with smartphone connectivity for music, GPS. phone calls and even more. This intercom has advanced noise control which ensures that the noises you don't want to hear stay blocked whilst the noises that should be heard are kept out in the open.