Just a few helpful tips when shopping for audio recorders. Range is very important. Make sure that your device is going to be able to pick up at the distance you need it to. If a device has a 30ft recording diameter for instance, it will record anything 15ft around it in any direction. Microphone sensitivity is a very key feature. Sensitivity will not only dictate the range of the device and the level of sound it can pick up, it will also play a large part in how covert the device can be. A device with a very sensitive mic will be able to record a close quarters conversation without ever leaving your pocket, giving it a much higher covert rating. Environment. This is the toughest element to get right because often you will have no control over it. If the environment is too large the device may not pick everything you need up and if the locale is too loud it may cause too much interference for the recording to be useful. Knowing the details about the environment before you choose your device is a must.