First of all, there is no device that makes you have Lucid dreams. They don't exist. Though this device can help you become lucid.
The REM Dreamer is very comfortable, well made, and with practice, it can work! You just have to have patience and not give up after a week. It takes work to learn how to lucid dream. You just fine tune the settings and improve your dream recall and reality checks to train yourself to become aware you are dreaming when you see a flash.