This was purchased for my grandbaby and it works perfectly! Once you add 3 AAA batteries, you push and hold the off/on button for 3 seconds and the on light comes on. You can then choose from 5 different sounds (lullaby, ocean, rain, heartbeat and just white noise) that have really clear sound and soothes baby (or yourself!) quickly. It has a great sleep timer that you can set for 15 or 30 minutes (a light indicates which one and changes when you push the button). The sounds are easily selected by pushing the corresponding button image and you can adjust the volume as needed.
Personally, I love the portability of the unit. You can clip it to cribs, car seats, stroller, diaper bags etc. The design is cute and its made of a high grade plastic that wipes down easily. Very happy with the purchase!
For more information click here