Preliminary: Remove the battery compartment cover and Insert (2) new AAA batteries. Rechargeable batteries may enhance the performance of the unit. 1. Flip the switch on the right side of the unit to tum “ON” the FM transmitter. 2. The unk allows you to choose from 20 different frequencies: 38.1, 38.3, 58.5, 58.7, 88.9, 90.1, 90.3, 80.5, 90.7, 90.5, 108.1, 108.3, 100.5, 108.7, 106.3, 107.1, 107.3, 107.5, 107.7 & 107.