If you are trying to maximise the range of your two-way radio, then you need to wear your radio so the radio's antenna sits above your shoulder. This will give you much better talk distance coverage, than if you had the radio sitting on your hip. When the radio is attached to your hip, your body absorbs a lot of the radio signal.
These radio harness cases are an adjustable chest pouch, so you can wear your radio high on your chest. The cases also have room for your wallet and any other possessions you may be carrying.
If you are using a satellite powered PTT communication system, such as the Icom ICSAT100, then it is an ideal practice to always have the radio antenna pointing towards the sky. This inexpensive chest harness enables you to achieve this best practice, to enjoy smooth uninterrupted communication.