Highly sensitive microphone amplification with ALC automatic level control, providing up to 1000 times amplification to capture weak sounds. Direct headphone output for real-time listening. Compatible with mobile phones for recording via 3.5mm interfaces. Built-in lithium battery supports charging with a standard mobile phone charger and offers 20-30 hours of continuous use when fully charged. For optimal performance, use with a high-directional microphoneavailable separately or can be self-made. Input and output interface: 3.5mm. Mobile phone interface: 3.5mm four-pole. Microphone gain: switchable between 40dB and 60dB. Headphone amplifier power: 105mW x 2 at 16 ohms. Built-in lithium battery capacity: 300mAh. Power input: 5V. Socket specification: 3.5x1.35mm. Dimensions: approximately 6.3 x 5.2 x 2.2cm. Material: plastic and metal. Color: black. Package includes: 1 x amplifier, 1 x charging cable, 1 x phone connection cable. Additional accessories not included. Note: Lighting effects and display settings may cause slight variations in color between the image and the actual item. Measurement tolerance: +/- 1-3cm.