The first thing I noticed about this sound machine is that it is very light weight. Like the title implies though, big sound for a tiny machine! This is great for travel. You can use the ac adapter or batteries which is good thing because I tend to lose chargers. They can't help me with that! I use the rain sound to sleep but there are 5 other sounds to choose from. Maybe you just want to drown those noisy people in the hotel room beside you? I have actually used products similar to this for years. It's nice to have a separate one for travel that doesn't take up much space. [This review was collected as part of a promotion.]