Hama Audio Adapter (2x 3-Pin 3.5 mm Jack Plug - 4-Pin 3.5 mm Jack Socket, Stereo Jack Adapter Connects 4-Pin Jack Headphones with Microphone or Headset to a PC or Laptop): Amazon.co.uk:
VISSQH 10Pcs 3.5mm jack socket, jack plug 3.5mm TRRS 4-pin audio plug for soldering 3.5 mm mini stereo jack plug Cable (30 cm)
DELOCK 65673: Cable Stereo jack 3.5 mm 4 pin male > Stereo jack 2.5 mm 3 pin f at reichelt elektronik
PremiumCord 3.5mm 4 Pin Audio Voice Audio Jack Cable - Allows Microphone Aux Headset Audio Connection Cable M/M Length 1.5m