Sennheiser's RS 175 offers an impressive range of features so that you can enjoy music and television to the fullest at a comfortable volume without disturbing those around you. The Bass Boost and Surround Sound listening modes will allow you to experience your home entertainment system like never before the former increases the audio bass response while the two virtual surround modes offer a more spatial and livelier stereo sound. Features Up to 114 d B SPL amplification. 2.4-2.48 GHz frequency. Up to 328 ft. range (line of sight). Jack - 3.5 mm. Easy-to-use, ergonomically designed controls right on the headphones. Switch between Dynamic Bass and Virtual Surround Sound listening modes to customize your sound depending on what you are listening to. Comfortable closed, circumaural headphones with adjustable headband. 18 hour operating time. Transmitter functions as charging dock (2 AAA Ni MH rechargeable batteries included).