它是什么？

A stretchy band often used in physical therapy.

它在哪里找到？

Physical and Occupational Therapists might have Therabands in their office or sensory gym. Classroom Teachers might also have extras around the room.

我该如何使用它？

You can use a Theraband in activities that require some resistance. Another common use is to tie it to the bottom of a chair or desk for students to put their feet against and push/bounce as necessary. This gives sensory input and lets their feet stay busy.