The Sena HD Speakers are designed to be used with the Sena 50S, 30K, 20S and 20S Evo Intercom systems.Up to 50% Higher Audio ClarityEnhanced BassNew Bevelled ShapeThe Sena HD Speakers come with the Sena SC-A0325 Premium HD speakers Type A which means that these speakers will deliver a crisp communication sound quality and a premium music listening experience. These speakers also come with a stunning increase in clarity and bass boost which means these speakers will give you a sound like you've never heard before. These speakers incorporate a low-profile bevel which helps to reduce potential ear-to-edge chafe. These speakers are designed to be easily fit in to any existing helmet speaker pockets. The Sena device's mobile app has been updated to enhance the output of the HD speakers which also includes a new Audio EQ pre-set.