[. . . ] Find a suitable location for the On / Off switch Be sure that it is within easy reach of the driver and can be operated safely from the seated position. Level Installation Instructions Frequency Selector Switch 88. 7MHz 89. 1MHz NOTE: The On/Off switch requires a flat surface at least 3/4" in diameter for mounting, with 1" rear clearance. [. . . ] If a local radio station uses the first frequency selected, use the other frequency. Set the level matching control so that the volume level over the speakers is the same as when listening to radio stations. If loud passages sound distorted, lower the Level Matching Control setting. FM200 User Guide and Product Data Sheet The Clarion FM200 is a two-channel stereo FM modulator with selectable FM frequencies, variable gain, and a remote on/off switch. It allows the addition of auxiliary audio sources to any FM radio (even those lacking auxiliary inputs). It can be used with DVD players, videocassette players, MP3 players, and more. On/Off Switch To use the FM200: 1) Turn the On/Off switch to the On position (This is the position with the "I" icon). Tune in either 88. 7 or 89. 1 (your installer can advise you which frequency setting is being used in your installation). Once you determine the correct frequency, it is a good idea to store the frequency using one of your radio's preset keys. [. . . ] Current Consumption: Operating Frequencies: 200mA 88. 7, 89. 1 FM Fuse rating (in Fuse/Filter box): 2A AGC Parts List: (1) FM Modulator Main Unit with integrated harness. [. . . ]