Purchased for 16,500 yen. Used once. I have two, so I'm selling one. Maroom's is a chair that strengthens your core. Inside, there's a balance ball, and just by sitting on it, you naturally straighten your back and train your core. The organic form and pleasant-to-the-touch cover blend in with the interior, making it look nothing like a training item. It's also recommended to use a balance ball chair instead of a regular chair for office work or studying. Stretching your hips, lower back, and shoulders is also effective for restoring concentration. Sitting with your pelvis upright enhances the effect on your back and abdominal muscles. Also, the non-rolling balance ball is safer because it's less likely to tip over, so anyone can use it with peace of mind. Size and Weight Height: 56 cm Diameter: 52 cm Weight: Approximately 1.85 kg The size varies depending on the amount of air inside the balance ball. When you sit on it, the balance ball sinks in, and the height becomes around 42 cm. Although there are differences depending on the user's weight, it can be adjusted with the amount of air in the balance ball. It is designed to match the height of a standard office desk (70 cm). Set Contents Balance ball × 1 Cover × 1 (Polyester 97.1%, Polyurethane 2.9%) Frame parts × 5 Rubber feet × 10 Air pump × 1 Pins × 2 Pin remover × 1 Instruction manual × 1 Made in Japan