StarTech.com 4 Position to 2x 3 Position 3.5mm Headset Splitter Adapter - headset splitter - 20 cm

Turns a 3.5mm audio output port into two distinct ports - one 3.5mm headphone jack and one 3.5mm microphone port. The MUYHSMFF Headphone/Microphone Combo Jack splitter (4-position 3.5mm to dual 3-position 3.5mm) is a headset Splitter Adapter features one 3.5mm Male (TRRS) and two 3.5mm (TRS) Female connectors, enabling you to add a mono microphone input, as well as a stereo output to your PC or Laptop, through a single 3.5mm audio port.

Price: 3.58 from Currys Business