The listings show support for common audio formats (AAC, FLAC, MP3, WMA) and specify USB-disk (mass-storage) support up to 64GB; some models also mention drive-change/mass-storage access for USB devices.
Several car-style receivers provide USB power for charging via the front USB port, commonly rated at 1.5A; front USB inputs are described as supporting device charging.
Most car and single-DIN digital media receivers place the USB port on the front panel; multiple listings explicitly note front-mounted USB access.
Listings reference Android Open Accessory (AOA) 2.0 compatibility, mass-storage/drive-change modes for USB drives, and use of USB as a digital audio source (via a built-in DAC) in wireless adapters.
Many receivers pair USB with a front AUX input and multiple line/pre-out terminals for expansion—examples include front AUX plus three pre-outs (front/rear/subwoofer) or three pairs of line outputs.
The listings explicitly mention USB-disk support (up to 64GB) and a drive-change/mass-storage class mode for accessing USB drives.
Motorcycle and marine listings emphasize front USB access for media playback and charging, and often include vehicle- or marine-specific installation or mounting kits paired with USB-capable digital media receivers.
At least one wireless transmitter/receiver listing describes a built-in DAC that accepts a USB connection from a computer to stream digital audio to the wireless transmitter, which then sends audio to a receiver.