Although for normal sport usage you are ok with the regular headset of your smartphone (wired or Bluetooth). But, we also understand the need for more specialized microphone / headset combinations.
It is important that the set you use is adapted for a smartphone (impedance 32 Ohm instead of 8 Ohm (most radiosystems)).
Some suggestions for wired (smartphone) headsets:
Boom microphone - headset https://www.ceecoach.eu/ceecoach-mono-headset-met-boom-microfoon.html (+/- EUR 27 - you need a conversion cable for iphone) This is a boom microphone with good sound quality (microphone and speaker)
Security type headset https://portofoontoebehoren.nl/product/headset-voor-mobiele-telefoons/securityset-voor-mobiele-telefoon/ (+/- EUR 18 - you need a conversion cable for iphone) With both headsets it is recommended to set the audio output (in the audio settings menu in the App to high)