Nokia headset / handsfree HDB-5 connector and schematics pinout diagram @ pinouts.ru
BRB Product _ Headphone Splitter, MillSO Jack Headset Adapter CTIA Audio Splitter Adapter Cable 2 Male to Female with Separate Microp - Walmart.com - Walmart.com
Kein Mikro beim Headset – Klinkensteckertypen OMTP – CTIA - eKiwi-Blog.de