beyerdynamic DTX 50 SW Trendline In-Ear Headphones (Black) (Discontinued by Manufacturer) 10 Hz to 20 kHz frequency response Portable black in-ear headphones built exclusively for mobile audio applications Designed to sit deep in the auditory canal for maximum, ultra-deep bass efficiency Noise-isolating design minimizes outside audio for better dynamic performance and clarity Includes 3 pairs of silicone ear pads in different sizes