Sena Industrial Bluetooth to Mesh Intercom Adapter for Phone or Tablet PC - MeshPort Red (One Size) | Wireless Communication for Motorcycle Riders & Outdoor Adventures

I use these as a soccer referee. When paired with Shokz BT headphones (OpenComm with the boom microphone), they are excellent for in-game communication. Since the Shokz are bone conduction, you'll still have full use of both ears-- even when someone is talking. There's also some noise cancellation going on, so you won't hear a full volume whistle, etc. Reception is generally great, though there is occasional interference at some venues (infrequent and doesn't restrict use of the system. Occasionally annoying, however.)Because these are connected to the headphone via Bluetooth, you don't have any wires. You can put this reciever anywhere -- though the upper arm or upper body appears to work well. Along with the stability of the headset, you have a system that moves with you, and one that you don't need to adjust or put back in every 2 minutes. It's like they were designed to facilitate what referees do -- even if that's not what they were built for.That said, these are the best set of referee coms I've used, and I've experienced almost all of them. The only complaint, and it's a small one, would be to eliminate the longer antenna and maybe find a way to run one around the outside of the module to cut down on the form factor. But other than that, these are fantastic.