Designed specifically with runners in mind, these Karrimor Band Earphones fit around the back of the neck to give you a comfortable fit when you're on the move. These earphones also feature a 3.94 ft. (1.2 meter) cable and three different-sized ear pieces to suit a range of users Different ear piece sizes included. Diameter: 0.4 in. (10mm). Frequency range: 20-20 Khz . Sensitivity: 90dB + 3dB. Imported.