Delayed post: I purchased the surveillance mic with the radio. Other Hams have told me that I sound muffled. I have to stop using the mic for this reason. I am not sure if the radio (CS580) can be modified to clear up the muffle? I have purchased the speaker mic to replace the surveillance mic. I will look for a surveillance setup that can plug into the earpiece.

Great quality and sound for the price.

This is a great surveillance Speaker Mic. Shows very little while you are wearing it. Sounds great on both end according to person(s) on other ends. Very reasonable price.

This is a great surveillance Speaker Mic. Shows very little while you are wearing it. Sounds great on both end according to person(s) on other ends. Very reasonable price.

I looked forward to getting this mic, as it makes using the radio less annoying to bystanders/vehicle passengers. The basic constructions seems to be OK, only time will tell, and the connector attaches without problems. The major problem for me is that both received and transmitted audio are very "muffled", very lacking in HF content. This makes it hard to understand some people whose voices are on the lower end of the audio spectrum. I tested the mic while using another radio as a "reference", and both TX and RX audio sounded as if they were coming through a pillow. Enhanced HF response would be a definite plus for this surveillance mic accessory.