Unopened item. I'm selling it because I won't be using it. Please consider purchasing if you understand that it has been stored at home. The instruction manual is torn. The size is semi-double. Since it hasn't been opened, the exact size hasn't been measured. I've attached photos, but please understand that there may be some slight errors. ■Size Width 120 x Depth 195 x Thickness 22cm ■Materials [Surface] Knit fabric (100% polyester), [Back] Non-woven fabric [Inside] Pocket coil spring, non-woven fabric, urethane foam, felt #Mattress #Pocket coil #Semi-double