I purchased this for my child (a second grader with a slightly large head), but the size was too small, so I only tried it on. The size is listed as 57-59cm, but it feels small. I measured the size, so I hope you can use it as a reference. Length: Approximately 17cm Width: Approximately 21cm Please purchase if you understand that this item has been stored at home. ◆ No pets, no smokers. ◆ I try to write about any stains, dirt, or scratches in the description, but as I am a novice, there may be oversights. Please understand this before purchasing. ◆ I take photos without any processing, but please refrain from purchasing if you tend to lower the rating due to differences in image. To prevent any trouble. ◆ I will report malicious complainers. ◆ Please feel free to ask any questions you may have ( *´艸｀)