1. High impedance sound record,get crystal clear sound from telephone line. 2. RJ11 phone connector shape, simply connect to telephone RJ11 port throught phone cable,no need attention the in,out port driection,the recorder will auto recognize. 3. Less charging, plug to use, built in special circuit gets power from phone system, but first time use need charge it, when connected to the telphone line, you may need take out charge it by USB charger every week if your phone call is busy,for normal use, you may need take it out to charge by USB charger every month. 4.Plug to use: plug the telephone line to the RJ11 port and turn power switch to on to start recording.You can place it in office,hotel,home with simple connection,then it will auto start recording when phone call made. 5.Cycle recording: support cycle of recording, when the memory reached fully, it will overwritten the oldest recorded files, works by first in first out mode. Memory: 32GB micro-SD card Recording Time: 7 - 30days after full charged Recording Formats: WAV Date and Time Stamp: Yes Battery: 700mah lithium battery Operating System: Windows XP/Vista/Win 7/8/Lunix OS / MAC OS Recording Bitrate: 192Kbps USB Port: USB 2.0 Frequency Response: 20Hz -20KHz Working Temperature: 0 - 40℃ Dimension: 59mm x 36mm x 25mm Colour:White Material:plastic Package Contents: 1 x RJ11 Telephone Recorder 1 x Telephone Line 1 x USB Cable