The FCC has changed the rules for wireless microphones. The 600 Megahertz spectrum/band has been re-allocated to commercial use only. Please contact your Audio/Visual supplier to see if your equipment will still be usable. This pertains to all forms of wireless microphones including lav/lapel mics. Rebates may exist to help defray the cost of replacing affected devices. While the legal deadline is 7/12/2020, commercial businesses in your community may have already started using the 600 band which means you could start experiencing problems soon.