The BackJoy SitSmart Pro Gel is an innovative, proven sitting device that provides natural, safe and effective back pain relief by optimizing your posture—anytime and anywhere you sit. The SitSmart Pro is cushioned with premium memory foam combined with soothing gel beneath the surface. Its portable and lightweight design works in any seat so you can feel more comfortable, supported and less fatigued after sitting for long periods of time. Works on any type of seat, hard or soft, including office chairs, sofas and car seats. Durable base and covering provide long-term use. Fits adults 100-300 lbs. SitSmart is designed to cup the pelvis itself, not the soft tissue around it. The standard size fits nearly all adults regardless of weight or height. Includes verified certificate of authenticity from the original brand manufacturer.