At 17” x 19”, it is a size designed for various purposes:
Using it at the fullest size, many men and women place it in their bed, between the cover sheet and the top mattress. Sleeping on it for 6-8 hours a night, you will revitalize the muscles around the back and the hips, with improved circulation.
During the day, the negative ions will slip away as you’re not absorbing any from the sheet. Consider wearing a bracelet to keep the flow continuing through your body.
Cut it up into usable squares to fit a cushion that can be placed on the back of your chair, back of your carseat, or a cushion you lay your feet. The back of the chair or recliner will help your back and hips; the back of the carseat will help those long-distance car rides or when you sit in traffic. Of course, resting your feet on the cushion will help feet, ankles, and up the legs into the knee area.