Glass hourglass, which measures exactly 15 min. In these 15 min. you can either practice reading, vocabulary or an instrument. I always had these agreements with my children: “now you practice 15 min. and then you can do what you want for half an hour.” That always worked quite well. If there is such a nice hourglass next to you, it certainly works even better.

The hourglass is 14 cm high and made of glass