Behind-the-neck headband won't interfere with your hairstyle; lets you wear a hat; establishes a new look on the street. Non-slip design stays on your ears, even during active sports; ideal for jogging, dancing, aerobics, blading and other activities you can now enhance with music. Mini-plug resists corrosion for maximum conductivity, minimum noise. 30 mm diameter drive units are larger than many portable headphones for deeper bass, lower distortion and wider dynamic range (frequency response extends down to a low 16 Hz). Ultra-small, ultra-light headphones weigh less than 2 ounces (55g) without cord; comfortable for hour after hour of wear.