Thank you for viewing. Xvive / XV-U4 Please consider this item as junk. I used this for studio practice once a month for several years, but it started malfunctioning, so I replaced it with a more professional one and am now selling this. The symptoms are that it connects if not moved, but the connection becomes unstable if either unit is moved. I suspect either the transmitter or receiver is faulty, but I don't have a spare transmitter or receiver, so I don't know which one is defective. (I don't think both are broken, but I can't confirm...) Please purchase only if you can repair it, or if you can use either the transmitter or receiver. There are no smokers around me. I used a case to carry it, so there are no noticeable scratches on the exterior, but there is some wear and tear. Thank you.