Function: Card Call functionColor classification: black graffitiRated power: 10WPackage type: Official standardReceiving distance: 10m and belowPower supply: Built-in lithium batteryShell material: plastic supportFormat: U disk TF cardConnection method: 3.5MM audio jack USB Bluetooth connection speakerAdjustment method: buttonSize: 230x95x115mmThis product is worn with a strap.Specifications:√ Built-in 3.5 mm audio port for wired or Bluetooth 5.0 wireless connection√ Playback time: up to 5 hours of wired and 4 hours of Bluetooth wireless connection√ Speaker driver: 40 mm√ Charging time: 2.5-3.5 hours√ Connection range: 33 feet√ Working frequency: 100Hz-20KHZ√Battery: Built-in rechargeable 3.7V 1200mAh lithium-ion battery√ Size: 230 * 95 * 115mm√Signal to noise ratio: ≥80db√ Distortion: ≤0.1%√ Built-in large speaker cavity for excellent sound quality√ Built-in passive subwoofer for excellent bass√Battery status can be displayed on the iPhone