Thank you for looking^_^ True Sleeper Low Rebound Mattress Exclusive Inner Cover Single The size is not specified, but It was sent at the same time as purchasing the True Sleeper Low Rebound Mattress Single. It is a new, unused item. Please refrain from purchasing if you are sensitive about home storage. Due to shipping arrangements, the inner cardboard will be removed and only the cover will be shipped. Although it is listed as "Rakuraku Mercari便" (Rakuraku Mercari delivery), it may be changed to "Yuyu Mercari便" (Yuyu Mercari delivery). Also, please understand that it will be folded small, compressed, and shipped within 3cm.