Builtin lithium battery that can be charged with a standard mobile phone charger. When fully charged, it delivers 2030 hours of continuous use. sensitivity microphone amplification with automatic level control (ALC). Up to 1000x amplification to boost weak sounds. Directly drive headphones for listening, and it can be connected to mobile phones for recording. All interfaces are 3.5 mm. Key features and benefits Long lasting power: builtin battery enables extended use between charges. Strong amplification: up to 1000x gain with ALC to maintain stable levels. Real time monitoring: headphone output allows immediate listening and monitoring. Phone recording ready: easy connection to mobile devices for on the go recording. Simple interfaces: all connections use 3.5 mm jacks for compatibility and ease of use. Compatibility and interfaces 3.5 mm interfaces for microphone input, headphone output, and phone connection. Compatible with devices that support standard 3.5 mm audio jacks for recording and playback. Performance notes sensitivity amplification helps capture faint or distant sounds. ALC automatic level control helps prevent clipping and keeps output balanced. Direct headphone monitoring supports realtime listening without external equipment. Use scenarios Field interviews and environmental sound recording: connect to a smartphone to record, monitor audio in real time, and use the amplification to capture quieter voices or distant sounds. Meetings, lectures, or conferences: amplify speakers in a room, monitor the session through headphones, and record to a mobile device for later transcription or sharing. Nature or wildlife observation: amplify subtle natural sounds for study or documentation, with easy phone recording and onthego monitoring. This description preserves the original product's functions, specifications, and 3.5 mm interface design, while presenting clear, customerfriendly information about benefits, compatibility, and practical use.