Description of Boeri Radioactive - Audio Dropliner for Vortex and Siren Helmets Since 1989 U.S. wintersports enthusiats have turned to Boeri for their productive headgear needs. Their innovative designs, world renouned quality, great off-the-shelf fit and wide assortment of colors and styles are a few of the reasons Boeri proudly remains the leadrer in wintersports helmets. The Boeri Radioactives are an audio-enabled Boeri dropliner for the Vortex and Siren helmets. This Audio Radioactives Dropliner replaces the existing dropliner (ear covers) in your Vortex or Siren helmet. Radioactives get you wired for sound. A volume control switch and mute button are standard, and a carrying case is included. Features: Compatible with Boeri Vortex & Siren helmets