Colorful hourglasses for a small price

The five hourglasses are as shown and cover from 30 seconds up to 10 minutes several short intervals from. (30 sec, 1 min, 3 min, 5 min, 10 min). They are not perfect, but processed properly. The sand trickles easily through, in the amount the watches are not on the same size of a millimeter, but that can get over easily.
We use clocks to in certain situations, to admit our four year old time feeling: how much time has yet to have breakfast when shall I come to dinner, how long does the brushing? As is very helpful that the hourglasses are provided externally with a second shell made of transparent plastic. The will not work miracles, but thrown down and roughly tackled they were already without damage.

Since the reviews vary so much and is probably of different products depending on the sender, I can add: I ordered through the shop "school bookstore Sieboldt".