StarTech.com Headset adapter for headsets with separate headphone / microphone plugs - 3.5mm 4 position to 2x 3 position 3.5mm M/F - Turns a 3.5mm audio output port into two distinct ports:
Amazon.com: VoiceJoy Standard 3.5mm Jack Smartphone Headset Adapter Cable Converter to RJ9 Plug for Cisco Unified Office Telephone 7970 7940 7941 7942 7971 etc : Electronics
Tactical Radio Connector Cable Headset: Peltor, TCI, TEA, Civilian Hel – Comm Gear Supply
Amazon.com: StarTech.com Headset Adapter, Microphone and Headphone Splitter - 3.5mm Male Aux to 3.5mm Female Audio & Mic Combo Jack Y Cable for Laptop / PC (MUYHSMFF) Black : Electronics
Amazon.com: ienza 2.5mm Male 3-Pole to 3.5mm Female 4-Pole TRRS Headset Jack Adapter Compatible with Panasonic Cordless Phones to Headsets or Headphones with a 3.5mm TRRS Plug (Mic & Headphone) : Electronics
Amazon.com: Headphone 3.5mm Splitter Mic Cable for Computer, KOOPAO Headset 3.5mm Female to 2 Dual Male Microphone Audio Stereo Jack Earphones Port to Gaming Speaker PC Adapter : Electronics
Amazon.com: D & K Exclusives Headphone Splitter for Computer 3.5mm Female to 2 Dual 3.5mm Male Headphone Mic Audio Y Splitter Cable Smartphone Headset to PC Adapter : Electronics
StarTech.com USB-C Headphone Splitter USB Type C Dual Headset Adapter w/Mic USB C to 3.5mm Adapter - USBC-AUDIO-SPLITTER - Audio & Video Cables - CDW.com
Headset Audio Cable 3.5mm for Computer Headset Adapter Mic and Audio Headphone 2 in 4 Cable for Gaming Headset to PC, Red Green Model without Buckle - Walmart.com