These turned up today.... Put one on the dash already to see if it works... I get terrible build up on my front screen, partly because it faces the sunrise (My house faces onto a large open green larger than a football field). So it gets pretty bad as the sunlight warms the interior of the car. Both pleased and disappointed... the bags are hefty and should do the trick if they work as advertised. There's a little window in the corner so you can see them start to turn colour as they absorb moisture. However... the bag to store them in when not in use is nothing more than a flimsy see through ziplock bag, and the dehumidifier bags themselves are only sealed shut with velcro, no zip. I've tested it by turning it upside down and giving it a little shake... and it does allow them to leak a little. I'd be far happier if there was a zip inside. But most of all... I really... really... miss my heated front windscreen from my old car.