Koss SB40 20Hz Communication Stereophone with Microphone

QZ99 Passive Noise Reduction Headphones

Koss Part# QZ99

Headphones/Earphones – Headphone - Over-the-head - Over-the-ear - Binaural - Wired - Ear-cup - Circumaural - Stereo - Phono - Mini-phone (3.5mm) - 8 ft Cable Length - 40 Hz Minimum Frequency Response - 20 kHz Maximum ...