The Arkenstone phone is equipped with an integrated horn, but a more powerfull regular horn is also supplied with the VARG EX and SM. Not compatible with the VARG MX 1.0 and MX 1.2. To install the horn: - Remove the right lower carbon fiber spoiler bolt - Install the horn onto the bracket using the removed bolt from carbon fiber spoiler, Torque: the horn bolt to 5 Nm. - Mount again the carbon spoiler sandwiching the sheetmetal bracket of the horn against the frame with the bolt supplied in the horn hit from the homologation kit box, Torque: the bolt to 5 Nm - Route the cable between the carbon fiber spoiler and the main frame rail, then connect it to the docking station routed through the triple clamp silicone guide. The bolt supplied with the horn must not be used to install the horn on the bracket directly, but to replace the removed bolt from the carbon spoiler.