It works fine with Rino 530Hcx. There is a single ear "ear-bud" = mono speaker. PTT = Push to Talk switch works the way it should with Rino 530. Price is acceptable(not bargain) for what you are getting. Uses 2.5mm 3-conductor plug (Mono speaker + mic).

I haven't had much time to use the earbud with microphone, but from what I have used it, it works well. It's fairly robust, the only thing I worry about is pulling too hard on the wires from the earbud to the GPS, like all stereo headset users can attest, it is too easy to damage the headset by accidentally pulling the wires. I do not know if this is the case here or if it would just pull out of the receiver. But other then that long term worry, the earbud/microphone works well.

Received this as a gift. It did not work with my Rino 530.
After back and forth with garmin we determined that the earbud and mike did not work.
Amazon refused to accept return as 30 days had passed since purchase date.
Beware!