If you’re doing a lot of important business conversation and agreement, you might need this A350R Voice Recorder from Safa. This device can disguised itself as a book case, thus letting you to record your conversation with others secretly. It adopts dual-stereo microphone and can record up to 247 hours of voice. Other features include pre-listening function, A-B repeat function, voice activated recording function, high- and low-speed playing support.