I purchased a ULX-D handheld system and there was a 1 inch diameter rubber ring that was included. It appears to clip over the antenna on the handheld, but I can't find it mentioned in the User Guide. What is it for?
In a bright environment, the metal battery charge contacts on the handheld can cause a reflection. The rubber ring is used to cover the battery charge contacts on the microphone for appearance purposes only - such as when the microphone is used on-camera. It is strictly optional and is not required for any other purpose.