Fitness Audio VHF Series is the best built fitness wireless microphone system hands down. The simplified clean design takes a beating and keeps on delivering. Transmitter circuit boards are coated with a marine grade sealer for additional sweat protection (Fitness Audio exclusive). Single 'ON/OFF' switch to minimize confusion and accidental battery usage. Our VHF systems are on VHF travel frequencies so they work in just about any small to medium sized city. Back-up transmitter are inexpensive, so pick up an extra with an extra headset to maximize the life of your system. This system is our best selling system in the US.