The DEH-S4220BT is designed to accommodate the Smartphone lifestyle. It has a built-in hands-free Bluetooth receiver. When using Pioneer Smart Sync with Amazon Alexa it opens a new world for this CD receiver. Using this application, you can broaden your access may it be wired or wireless. The receiver is equipped with two RCA pre-outs at 4V each, with a built-in amplifier. It has a 13-band customizable graphic equalizer and when utilizing Pioneer Smart Sync increases to 31 bands. Features include Pioneer Smart Sync App with Amazon Alexa, wired Android Auto and Apple CarPlay, Pandora, and Spotify via Bluetooth, and has USB direct control for iPhone.