Tumbler is a toy for children. It entertains children and it could also solve some problems caused by our habits. For example, when mother is occupied in the kitchen, it is very often that she'll spill the soy sauce bottle. The interior structure of the tumbler could solve this kind of problems. 

There's a rotatable cap at the bottom. Due to the fact that molecular of oil is bigger than water, the oil won't spill out when the container is upside down. 
Just whirl the cap then you could use it. The port is so small that only when you squeeze it then the oil will come out. Also, because of the pressure, the liquid won't be easily to seep.

For travelers who always need toiletries when travelling, silicone could wrap the tooth brush and tooth paste; besides, it could also become a rinsing mug. With a good use of the material, there won't be problems of weight or other problems like slit caused by squeezing. 

Scroll down from the top of the slit until the length you need, it could become a convenient cup.