These 9 cm sand timers are made of a hard perpex inner with a plastic outer shell in case of mishaps. They are colour coded and have approximate times embossed on the lid of each.
We started using them for brushing teeth, as most parents do. But we found that they can be used for so much more, as the idea of racing against time fascinates our kids - our current record for taking a bath is under a minute. (with the caveat of "we can wash properly tomorrow")
Timers available: 30 sec, 1 min, 3 min, 5 min and 10 min.