This round cushion uses high-resilience urethane to distribute body pressure. - Size: Approximately 38cm in diameter, hole in the center is approximately 9cm in diameter, approximately 17cm thick - Weight: Approximately 450g - Material: High-resilience, high-density urethane - Cover: Removable and washable - Storage: Fits in a tote bag I purchased this in September of this year to prepare for childbirth. I recently gave birth without any problems, and I took it to the hospital, but I didn't need it because the hospital had its own, and fortunately, I didn't need to use it after giving birth either, so I'm offering it for sale. I used it for about 30-40 minutes in the car when going to and from the hospital, and I sat on it 2 or 3 times, so it's almost like new, but please refrain from purchasing if you are overly concerned about its condition. *It will be sprayed with disinfectant, dried, and then shipped in a compressed state. I hope this will be helpful to someone, such as those who are about to give birth. I have a newborn, so my replies may be delayed. I will try my best to respond quickly, but I would appreciate your understanding.