The Pioneer DEH-S5250BT is a single-DIN car CD receiver with dual Bluetooth, USB, and smartphone connectivity. It works with the Pioneer Smart Sync app, which integrates your smartphone for navigation, music streaming, and other features. 
Key features
Dual Bluetooth: Connect and control two phones simultaneously for hands-free calls and music streaming from either device.
Pioneer Smart Sync app: Use your smartphone as a touchscreen remote to control various functions of the head unit, including accessing navigation, communication, and music apps.
Spotify control: Dedicated integration lets you play, pause, skip, and browse Spotify content directly from the head unit when connected via Bluetooth or USB.
Audio quality: Offers a 13-band graphic equalizer for detailed sound tuning, FLAC lossless audio file playback, and an Advanced Sound Retriever for compressed audio.
Connectivity: Features a front-facing USB port for direct control of iPhones and Android devices, as well as a front auxiliary input.
CD player: Includes a built-in CD player for traditional media playback.
Variable color illumination: Customize the display and key illumination with a choice of over 210,000 colors to match your car's interior.
Siri Eyes Free: Allows iPhone users to access various Siri functions via voice commands.
USB quick charge for Android: The USB port provides up to 1.5A to charge Android smartphones quickly.
Karaoke function: A "Vocal Cancel" feature reduces the vocal track from songs