High impedance sound recording, captures o from telephone lines.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 signal.Low charging requirement, plug-and-play operation with built-in special circuit that draws power from the phone system. First-time use requires charging. For heavy call usage, recharge weekly using USB charger; for normal usage, recharge monthly via USB charger.Plug-and-play: connect the telephone line to the RJ11 port and turn the power switch to on to begin recording. Can be used in office, hotel, or home with simple setup, automatically starts recording when a call is made.Loop recording: supports continuous loop recording. When the memory is full, the device overwrites the oldest recorded files in a first-in, first-out manner.Memory: 32GB SD cardRecording Time: 7 to 30 days depending on usage after full chargeRecording Format: WAVDate and Time Stamp: YesBattery: 700mAh lithium batteryCompatibility: Windows 7/8/10, macOSRecording Bitrate: 192KbpsUSB Port: USB 2.0Frequency Response: 20Hz - 20kHzWorking Temperature: 0C - 40CDimensions: 59mm x 36mm x 25mmColor: WhiteMaterial: PlasticPackage Contents:1 x RJ11 Telephone Recorder1 x Telephone Line1 x USB CableOnly the above package content, other products are not included.Note: Light reflection and different display settings may cause slight color variation between the item and the image. Measurement error allowed within +/- 1-3cm.