I have opened the item, but it has not been used. The box is damaged. I am selling it because the size doesn't seem to fit my home chair. ZABUSHION ENZA Zabushion Round Cushion, Round Cushion, Seat Cushion, Ultra-Thick, Made in Japan, Premium Fiber, for Lower Back Pain, Chairs, Wheelchairs, Zazen Cushion, Meditation Cushion, Thick, Gift, 40x40x5.5, Washable, Round Model (Black) [Specialized Seating Brand / 4.5cm Thick Filling] Responding to requests for "1-2cm more thickness," this product overwhelmingly solves the problems of flattening, bottoming-out, and stuffiness of previous products. It is chosen by those who are particular about environments where they sit for long periods, and features ultra-thick, made-in-Japan fiber with excellent pressure distribution and breathability that is resistant to flattening. [Development Background of the ENZA Model] This new model addresses the concern that "the hole looks noticeable" with typical round cushions. It combines an oval structure that is gentle on the coccyx with a design that naturally blends with the cover. Because of the oval shape, countless combinations such as vertical, horizontal, shallow, and deep are possible, making it easy to find your preferred position. [Long-Awaited Makuake Product Release] In the crowdfunding campaign "Makuake" held in April 2025, we received support from 468 people for 6.3 million yen (achievement rate: 6,310%), achieving results far exceeding expectations. [Ultra-Thick, Made-in-Japan Premium Fiber] (1) Made in a top-class Japanese factory that developed the world's first fiber material. Despite being a material that is sensitive to heat and difficult to process, it achieves thick and excellent elasticity with its unique patented technology. (2) Uses a high-performance material with a proven track record of being used in 5-star hotels, due to its excellent pressure distribution. [Always Ultra-Pressure Distribution] Eliminates the bottoming-out feeling of previous products, and is a 4.5cm ultra-thick fiber material that is easy to use on chairs or on the floor. Comfortable seating environment anytime, anywhere.