Phone Recorder: Compatible with all analog phone lines, this device supports high-impedance recording for clear sound quality. Loop Recording: Features first-in-first-out recording; when the storage is full, the system automatically overwrites the oldest file. RJ11 Interface: Connects to the phone line via RJ11 port and automatically detects signal input and output. Smart Charging: Equipped with a Micro USB interface for easy charging; powered by the telephone system through ASIC technology. Simple Storage: Supports external memory card (up to 32GB, not included) for storing WAV format o files; recordings can be accessed directly via U disk function. Package Includes: 1 x Phone Call Recorder 1 x Cover 1 x Data Cable 1 x Telephone Wire 1 x User Manual Item Type: Phone Call Recorder Item Model: TELREC01 Product Color: White Memory: Supports up to 32GB memory card (card not included) Telephone Interface: RJ11 Charging Interface: Micro USB Loop Recording: Supported Data Reading: Recording files can be directly read via U disk function Supported Phone Types: All analog phones o Format: WAV Working Temperature: 0 - 40℃ Battery Type: Built-in 3.7V 750mAh lithium-ion battery (model: 14500) Battery Capacity: 750mAh