Straw Tumblers 330 ml (2)
Not just for children. I also spill my drink now and again... Not only does the seal stop any spills when you knock it over, but the silicone valve seals up when the straw is pulled out, to prevent drips.
You can use any size or thickness of straw with the tumblers.
After a fundraiser party that I ran a few years ago, they became a huge hit with parents of Downs children. Children with Downs need extra support to develop clear speech, and often use a programme of drinking through straws of different thickness to develop mouth control and precision, and therefore to help with speech.
Straw not included, but any can be used.
8.3 cm diameter x 11 cm high.
Here's my US colleague Susan Pittser showing your the product with its great dripless straw feature. The larger size she mentions is not available in the UK: