2 Pack CE Tech In Ear Headphones W/Carrying Case For Smartphones & MP3 Players. This item contains: 1 pair of symmetrical headphones: 3.9 ft. cable; 3.5 mm gold-plated connector; high-grade silicone replacement gels in 3 sizes; and one carrying case. This item works with MP3/CD and Smartphones. There is a 20 - 20 000 HZ frequency range; 102 dB sensitivity; 16 Ohm impedance; 10 mW maximum power input.