The Gemini UHF-01HL is a single-channel wireless system with a combination headset and lavalier transmitter that s perfect for presenters and active entertainers who need hands-free performance. The UHF-01HL offers high-quality voice reproduction with incredible clarity and reliability at a surprisingly low price point. The lower range of the bandwidth starts at 500mHz and the upper bandwidth stretches up to 950mHz offering you multiple frequencies to choose from. You can easily connect external devise via the 1/4 output jack and the rugged UHF receiver has a 150 dynamic operating range making it ideal for bars clubs auditoriums and places of worship. F1 works in the 517.6mHz frequency. F2 works in the 521.5mHz frequency. F3 works in the 533.7mHz frequency. F4 works in the 537.2mHz frequency.