High impedance sound recording, captures audio from telephone line. RJ11 phone connector design, easily connects to telephone RJ11 port via phone cable. No need to worry about input or output port direction; the recorder automatically recognizes the connection. Low charging requirement. Plug and use – built-in special circuit draws power from the phone system. First-time use requires charging. When connected to the telephone line, recharge weekly via USB charger for heavy call volume; for normal use, recharge monthly via USB charger. Plug and record: Connect the telephone line to the RJ11 port and turn the power switch on to begin recording. Suitable for use in office, hotel, or home with simple setup. Automatically starts recording when a call is made. Loop recording: Supports continuous loop recording. When memory is full, the device overwrites the oldest recorded files in a first-in, first-out manner. Memory: 32GB SD card Recording Time: 7 to 30 days depending on usage Recording Format: WAV Date and Time Stamp: Yes Battery: 700mAh lithium battery Compatibility: Windows 7/8, macOS Recording Bitrate: 192Kbps USB Port: USB 2.0 Frequency Response: 20Hz - 20kHz Working Temperature: 0°C - 40°C Dimensions: 59mm x 36mm x 25mm Color: White Material: Plastic Package Contents: 1 x RJ11 Telephone Recorder 1 x Telephone Line 1 x USB Cable Only the items listed above are included; other items are not part of this package. Note: Lighting and display differences may cause slight variations in color between the image and the actual item. Measurement tolerance: +/- 1-3cm.