It is made of silicon and can be washed and used many times. A microwave oven can be used. Useful for subdividing side dishes for lunch. 

*Do not heat for more than 20 minutes even if it is below the heat-resistant temperature 
*Open flame/Oven toaster not supported 

* One size (approx.) : -Upper surface 64 x 60 x height 30 mm (bottom surface 46 x 42 mm) 
* Heat resistance : 230 degrees / cold resistance -30 degrees 
* Materials : Silicone rubber