It was a little bit big for our 4 year old, but worked perfectly in the end. He ‘kicked’ the habit with this product after about 2 weeks of wearing it during the day and night and then we left it on at night for a few more days. Assuming each kid is different, (cried the first night and complained the first couple of days), but he got used to it after a couple of days and then just resigned himself to stop. Could tell he didn’t even notice it by the 4th day.
Having tried a bunch of other products, this really seems to be the only that works because it takes away the child’s choice to thumb-suck or not. When we used the nail stuff, he just sucked it off because not having his thumb was apparently worse than tasting the nastiness and charts were no help since the thumb-sucking was not something he was aware of; it just ended up in his mouth all the time.
I also reached out to the company for advice in the beginning and they were very responsive + checked back after 10 days to see how things were going.