KOSS BT740iQZ On-ear headphones Bluetooth® (1075101), Corded (1075100) Black Noise cancelling Headset, Volume control | Conrad.com
Amazon.com: Koss Porta Pro with Microphone and Remote On-Ear Headphones, in-Line Microphone and Touch Remote Control, Collapsible Design, Wired with 3.5mm Plug, Black and Silver : Electronics
CS340BT QZ Wireless Communication Headset - Koss Stereophones