Brand new and high qualityBe able to record both sides of a telephone conversationGreat for recording lectures， meetings， interviews， discreet & covert spy recordingWith dictaphone functionRepeating read & loud speaker functionMP3 player functionLarge LCD with backlightBuilt in speaker & microphoneExtra microphone enhancing additional efficacyMemory: 8GBMaximum recording time: about 2320 hoursRecord format: MP3Support MP3/WMA/WMV /ASF， etc.Powered by 2 AAA batteriesDimension:107mm x 28mm x 17mmInstruction:1. OS support: WINXP， VISTA， 2000， WIN7( 32 bits )2. Voice recording: When it can't record the voice， please check whether the disk is full or not. If it is full， please remove or delete some contents to save room for new record or charge the device. ( In low electric quantity， the device can not be record voice. )