Review on SuLiao 2 Minute Sand Timer: Colorful Hourglass with Purple Sand for Kids, Games & Décor by Kimberly Khaltai

The aim was to use them to control my personal time with the patient so it wasn't obvious. They are used in air-conditioned interiors and doctor's offices to control humidity. I didn't expect them to be perfect or accurate, but the sand sticks to the sides. As a result, there is often a section left in the top hourglass until you tap one. Well, unless you look closely you have no real idea if it might stick together or not and when. I bought 4, all 4 behave the same, so this is not a single unit defect. This will most likely work for a kitchen situation where you're watching the appliance so you don't overcook. You would see the visible clumps and could gently tap them to get them flowing.