Parents and students often are seeking common stress relief tools. Here are some ideas. If it is a manipulative tool your student is seeking, please check with the Lead Teacher before sending your child in to school with it.
Here is the ever popular kinetic sand - diy version. Of course you can find it at Target and Toys R Us too.
Aaron's thinking putty can be found locally, but here is a link to Amazon to read about and see it and order if you wish.