The Sennheiser CX 300 II Precision are earcanal-style headphones from Sennheiser's CX Series. The earphones utilize dynamic driver systems to deliver powerful bass-driven stereo sound with improved clarity and dynamics. They are designed with an 1.2m asymmetrical cable and come with 3 sizes of ear adapters for a comfortable and personalized fit to block out background noise. The CX 300 II Precision offer 113dB sensitivity, 16-ohm impedance and a frequency range of 19-21,000 Hz. They include a convenient carrying pouch for storing the headphones when not in use and are also available as a travel model with a double mono adapter for in-flight entertainment systems. The earphones are available in black, silver, red, pink, or white and come with a 2 year limited warranty.