My daughter had quit sucking her thumb during the day, but needed some help at night while sleeping. We tried an old cut up glove, but it was hot and fell off easily. She really wanted to quit.
We explored many options and found most to be very expensive. I was delighted to find this device at a low price. It is snug, lightweight and comfortable. It does not fall off easily, but could be stretched out over the thumb if the child wanted to take it off (that's why it's important to have the child on board w/ wanting to stop).