Sony Lightweight Behind-the-Neck Active Sports Stereo Headphones Lightweight, behind-the-neck design - Ultra-small, ultra-light headphones weigh less than 2 ounces comfortable for hour after hour of wear Large drivers for powerful sound - 30 mm diameter drive units are larger than many portable headphones for deeper bass, lower distortion and wider dynamic range Comfortable foam ear cushions - The unique Ear Loop is easy to use while affording a comfortable and secure fit. Simply siide over the ear and slide into position Single-sided cord for eliminating tangles - Behind-the-neck headband won't interfere with your hairstyle; lets you wear a hat; establishes a new look on the street Standard 3.5mm mini plug for wide compatibility - The 3.5mm stereo mini plug is compatible with CD players, MP3 players, and most other consumer audio devices