I use the Plantronics M175 headset for Siemens Gigaset C45 handset. Works fine, very good speech, hearing and wearing quality, and the plug will fit well with no loose contact or slipping. Mechanical ok, but only for a few days in use, therefore no long-term experience. Plantronics is recommended in the manual of the phone and is also common in the professional field, so I got it and was not disappointed. Buy recommendation!
