81W DUAL-PORT FAST CHARGING - Charge a phone and a laptop at once via PD 45W and QC3.0 36W ports. Independent twin circuits keep both running at full speed together, with no power sharing. An on-screen display shows your vehicle voltage at startup, and built-in over-current, over-voltage, short-circuit and overheat protection keeps both the transmitter and your devices safe ONE-TAP BASS MODE - Press B to switch BASS mode on or off and add depth and impact to low-frequency output. BASS lifts the bass only, leaving voices and podcasts clear. For the cleanest signal, tune to 87.5-88 MHz or 107-108 MHz where no local station broadcasts BLUETOOTH 5.4 & HANDS-FREE CALLS - This car Bluetooth transmitter pairs fast and reconnects automatically. CVC noise reduction helps filter road and wind noise on calls. One button answers, rejects, ends or redials calls - hold to activate Siri or Google Assistant USB & TF CARD PLAYBACK - Play your own music without a phone. Plug a USB flash drive up to 64GB or a TF card up to 32GB into the transmitter and it plays MP3 and FLAC files through your car radio. Dedicated Previous and Next buttons skip tracks, and the mode button switches between USB, TF card and Bluetooth. The charging ports stay free while a drive plays 12V-24V WIDE COMPATIBILITY - Fits most cars, SUVs, vans and trucks with a standard 12V/24V cigarette lighter socket and FM radio. Deep or loose sockets may need the plug pushed fully home