Koss PRO4AA Specifications

1970 : PRO4AA set the standard for full-size professional headphones.
Comfortable Over-Ear Fit : Large, cushioned ear cups surround your ears for a comfortable fit, helping you stay focused on the music through extended listening sessions.
Limited Lifetime Warranty : Every PRO4AA is backed by Koss’ Limited Lifetime Warranty, reflecting our commitment to the headphones we build and the listeners who wear them.
5mm - 6.3mm Compatibility : Connect to a wide range of audio equipment with the included 3.5mm plug and 6.3mm adapter, from portable sources to home stereo components.
Passive Noise Isolation : The PRO4AA over-ear design and cushioned ear cups help block outside distractions, keeping you focused on your music without electronic noise cancellation.
High-Fidelity Audio : Hear your music with an extended 10–25,000 Hz frequency response, delivering deep bass, detailed mids, and crisp high frequencies across a wide range of sound.
Iconic Design : One of the most recognizable headphones around the world, PRO4AA carries forward decades of headphone innovation with a distinctive over-ear design built for serious listening.
Professional 250-Ohm Impedance : Designed for serious listening, The PRO4AA features 250-ohm impedance for use with compatible home audio equipment, amplifiers, and professional audio gear.