This little alarm is great!When I put it my pillow case, between the pillow and mattress, it vibrates strongly enough to wake me from even deep sleep. Being able to add annoying digital trolling sounds is a bonus if you want both types of alarm.That said, you have to use it properly or it won't be of any use. If it's sitting on a nightstand or just lying on the bed somewhere, it will never wake you up. Once you put it under your pillow, however, it becomes a powerhouse. Even with earplugs I can hear the alarm, and the vibrations were so strong I had to choose a gentler shake.Battery use is my only concern. My last shaker alarm had an internal battery, while this uses AAAs. They last long enough, but it's inconvenient to not be able to just plug it in to charge. That's really my only downside, though.

Well I did a test run, placed it under my pillow and the vibration is definitely felt through the pillow itself. The real test will be when I am in a deep sleep let's see. My only complaint is that the new batteries that were included in the pkg were dead! Not cool... good thing we always keep batteries in the house so I was able to do the test run. The size is great! The picture makes it seems like the item is big but it's not. It literally fits in the palm of my hand and I am a female.