What a GREAT set of timers! Well made and colorful. Description says these are made of glass but they feel like plastic to me, but I’m not an expert on the different types of glass so I could very well be wrong. Not only are these perfect for getting my Grandkids up and at em, but I use these for exercising also. When doing planks, it’s more fun to watch the sand drop than it is staring at the floor wondering how much longer, lol. Honestly, I find these very soothing and keep one on my desk, it’s very calming and soothing to watch. Sometimes, in this day and age, we forget to take it slow and forget to take the time to just sit and reflect. These truly help. My daughter wanted to take mine, I told her to get her own! This is a great value!