[Sleeping comfort] Firm and hard sleeping comfort [Reason for long-lasting use] ① The cover can be washed at home.If dirt gets stuck during use, you can remove the cover and wash it with water at home. You can also purchase just the cover, so you can replace it and use the mattress for a long time. ②In mattresses where the cushioning material can be replaced, the cushioning material is the first to reach the end of its lifespan. Since the cushioning material and the coil are separated, only the cushioning material that has reached the end of its life can be replaced. *We plan to start selling cushion material parts sequentially. ③ Coil units can be replaced. You can replace the coils to suit your sleeping comfort preferences, which change with your age and lifestyle. If you notice wear and tear after using it for a long time, you can just replace the coil unit. ④The outer cover has been changed to a knit fabric that feels comfortable to the touch. The texture has been improved by using knit fabric.