OPERATION Tuning: 1.Press the POWER button to turn on the TRANSMITTER. 2,A single press of the Up or Down tuning button will change The frequency up or down, @ © Specifications Type: FM-Stereo TRANSMITTER Output Power: 250 4 MAX Batteries: 3 vol AAA/UM-4 size's Dimension 82x50x33mm Weight: 128g Notice: The changes or modifications not expressly approved by the party responsible for compliance could void the user’s authority to operate the equipment.