Type of Interface: USB 3.5 mm audio socket frequency is the connection mode. Range of Sound: 60 Hz to 15 Hz Power Output: USB 5V Senior: 70 dB Power Supply Mode: External Battery Distribution Is Necessary Sound Channel: 2 Operation Mode: USB Bluetooth Protocol: No Effective; Number of Horns: Two Distance: 80 mAh Capacity: 8 hours of non-play The case Material: Box Body Made of Plastic; Appearance Made of Plastic Measurements: 78 * 80 * 125; Weight: 0.3 Voice Prompt and Call Function