[. . . ] [. . . ] 1. 4 oz including rechargeable battery Technical Data Modulation Carrier frequencies AF frequency response THD AF signal-to-noise ratio Max. 11 h 1. 4 oz including battery pack Product Variants HDI 92 P Two-channel stereo receiver (ch. 2­250 kHz) continued HDI 92 P Supplied Accessories Rechargeable battery BA 90 Optional Accessories Spare rechargeable battery Charger for one BA 90 European version US version UK version Charging units for up to ten BA 90 up to twenty BA 90 Plug-in mains unit for L 92 charging unit European version USA version UK version NT 92 NT 92-120 NT 92-UK L 92-10 L 92-20 L 90 L 90-120 L 90/UK BA 90 Product Compatibility Infrared Systems operating on 95 kHz (channel 1) or 250 kHz (channel 2) Sennheiser Electronic Corporation, 1 Enterprise Drive, Old Lyme, CT 06371 Telephone: 860-434-9190 · Fax: 860-434-1759 · Web: http://www. sennheiserusa. com Sennheiser Mexico: Av. Fax: (525) 639-9482 Sennheiser Canada: 221 Labrosse Ave, Pte-Claire, PQ H9R 1A3. [. . . ] [. . . ]