They’re really simple to operate, so your kids can do it themselves (which as you know is a HUGE deal for them). When they start either washing their hands or brushing their teeth, they hit the button with either the picture of a hand or a picture of a tooth on it. The invisible timer counts down 20 seconds for hand washing and 2 minutes for teeth brushing. While there is still time remaining, the green light flashes, increasing in speed the closer to time it gets. When they’re done, it turns red.
It requires 3 AAA batteries (not included), and can easily be stuck or screw mounted to a wall near your bathroom sink. You can pick one up for just £4.99.
Source: Oh Gizmo!