High impedance sound recording, captures audio 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 card Recording Time: 7 to 30 days depending on usage after full charge Recording Format: WAV Date and Time Stamp: Yes Battery: 700mAh lithium battery Compatibility: Windows 7/8/10, 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 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.