This is a gently used Shure BLX4 wireless microphone set with PG458 mic. This was only used a couple of times and then stored away. It is in great working condition and not a refurbished unit. The frequency is 518-542 MHz. Shipping is free within the Continental US or local pick-up. Please feel free to contact me with any questions you may have prior to bidding to avoid and prevent any confusion or misunderstandings. See my 100% feedback rating for references.