I bought this, but I haven't gotten into the habit of using it, and it's a waste to just leave it sitting around, so I'm offering it for sale. I've used it about 5 times. This product is excellent for maintaining good posture and allowing you to sit for long periods with your pelvis upright. It's recommended for those who do a lot of desk work, as sitting on it for extended periods can help prevent stiffness in your lower back and shoulders. It's also recommended for pregnant women. As your belly grows and your pelvis shifts, leading to lower back pain, using this product can help keep your pelvis upright, which reduced my lower back pain! It's lightweight and easy to carry around. Backjoy Posture Core Material: [Surface] EVA [Back] Synthetic Polypropylene Country of Origin: China Size: [Length] Approximately 14cm / [Width] Approximately 39cm / [Depth] Approximately 34cm [Suitable Weight] Approximately 55kg to 135kg Thank you very much!