Push-to-Talk ring accessory for Wisycom wireless microphones. The PTT305 sits between the microphone body and capsule to enable PTT control on the MIC. Described as high-profile with a 50 mm height to allow mounting of a foam windshield. Listed as compatible with MTH400 and MTH410 models. The page also mentions a PTT501 variant; no further technical specifications or accessory details are provided on the page.