Feature: This S3 seat cushion is our hot sale cushions in Japan and Korea which received good feedback. The advantage of this cushion is the protection of the coccyx. This seat cushion is hollow in the middle and wrapped in the back to protect the coccyx. It is especially suitable for the people who sitting in the office for a long time. The special design will make you fell hip wrapped and relieve the pressure of back when you sit on it. The inner is total 100% pure memory foam and it is the key factor why many companies prefer to work with us for a long time.