Combining quality, style and big sound merge in a body so slim it can be slipped in everywhere the Philips bt3500b/37has it all. Built-in NFC technologies makes smartphone pairing as easy as a touch. Equipped with Bluetooth so you can enjoy your favorite tunes from any location. It's Built-in rechargeable battery allows you to enjoy great music with the freedom of portability now. With its Built-in microphone, this speaker also works as a speaker phone, When a call comes in the music is put on pause and you can talk via the speaker. Anti-Clipping lets you play music louder and keeps it high quality, even when the battery is low. It accepts the input signals from 300mV to 1000mV and keeps your speakers safe from damage by distortion.