Legendary Sennheiser Voice Clarity, ensuring a clear and natural sound experience. Sennheiser ActiveGard technology protects users against acoustic injury caused by sudden sound burst on the line. High-quality neodymium speaker for outstanding HD audio quality. Ultra noise-cancelling microphone filters out background noise for perfect speech transmission. What's in the box SC 665 is premium wired headset with 3.5 mm jack connectivity for smartphone and tablet use.