Power in your handDeveloped with twin 48mm neodymium drivers and a passive bass radiator, this small speaker has nothing small when it comes to sound. By increasing low frequency, Edifier’s MP233 produces sound quality for a speaker twice its size.Smart syncNear Field Integration (NFC) allows you to simply connect your smartphone to the MP233 by tapping your device to the speaker, or by simply being in its proximity. No need to re-sync your smartphone every time you want to listen to music. And with Bluetooth 4.0 you now have a larger area to move around without loosing connection.Must have featuresWith a built in 12hr li-ion battery you can use the MP233 all day long – even at work. The incorporated microphone gives you the freedom to take conference calls through the speaker.More optionsNot only can you connect through Bluetooth 4.0 but also through a micro SD card. Upload thousands of songs to a micro SD card and listen to music on the go without filling up storage on your smartphone. You can also connect devices with a 3.5mm AUX cable.&AUX in: YesAmplifier: Built-inAudio output channels: 2.1Bass adjustment: YesBattery life (max): 12 hBattery technology: Lithium-Ion (Li-Ion)Battery type: Built-inBattery voltage: 5 VBluetooth: YesBluetooth version: 4.0Built-in microphone: YesCard reader integrated: YesCompatible memory cards: SDConnectivity technology: Wired & WirelessDepth: 3.6 cmDesign: RectangleDriver size: 4.8 cmFrequency range: 200 - 20000 HzHeight: 7 cmInput sensitivity: 900 mVInterface: Bluetooth/3.5 mmMagnet type: NeodymiumNear Field Communication (NFC): YesNumber of drivers: 2Power source type: batteryProduct type: 2.1 systemRMS rated power: 9 WRecommended usage: UniversalSignal-to-Noise Ratio (SNR): 80 dBVolume control: DigitalWeight: 450 gWidth: 18.2 cm