The 9mm drivers of these headphones offer a high-quality sound output, while the OFC Litz wire ensures audio clarity. The SE-CL25DN headphones come with three interchangeable ear tips. This variety allows you to obtain a customized in-ear fit. These headphones can be used with most MP3 audio devices, as well as iPhones and iPods. This headphone differs from the lower cost SE-CL21M-J-K model in that it has a neck strap (which is convenient for use with smaller MP3 players). These headphones lack the flagship SE-CLX50's 13.5mm driver (for more dynamic bass), larger 5-24,000 Hz frequency range, silver plated cord (for clear high frequencies), larger 100mW max power capacity and larger 125dB sensitivity. The Pioneer SE-CL25DN headphones comes in a light purple color.