The Qualstuff Fidget Spinner spinner is one such device. It looks more like a toy but it is an excellent stress buster. The size of the spinner is smaller than expected but it adds on to the portability.
The video shows how my five year old daughter spun the spinner and also the spinning time. For a five year old, if the spinning time is around one and half minutes, for an adult, it can definitely be more. If you closely watch the video, you can understand how restless my kids are, but this item just hooked them to it.
It is portable.
It is easy to use.
The spinning time is also pretty good.
The material is durable.
Small parts are not easily detachable.