All series 2 wireless products operate in the 1.9 GHz range. All 8000 and F1 series products operate in the 540-570 MHz range. Prior to August 1st, 2014, Anchor Audio wireless products were manufactured and operate in the 682-698 MHz range. This corresponds with products in the 7500 and U1 series. In Europe our products operate in the 863-865MHz range.