Pioneer DEH-S31BT features compatibility with Pioneer's exclusive Smart Sync app. Experience additional features by downloading the Pioneer Smart Sync app to your smartphone and syncing with your receiver. Smart Sync allows you to engage with your receiver in a similar fashion as high-end touchscreen units with a customizable UI and navigation app link. Pioneer Audio receivers feature built-in Bluetooth enabling both hands-free calling and audio streaming. You can also listen to music from your Android device or USB flash drive via the front USB port. Built-in MOSFET amplifier delivers up to 50 watts to each speaker (up to 4 speakers). A built-in CD player allows you to enjoy music from your CD collection.