Q: Which pillow is right for me? A. Please refer to the following. Q. How should I choose the height of the Brain Sleep Pillow? A. Please refer to the following. In addition, in the following article in the magazine, we conducted a survey of our regular users and introduce which height customers choose based on their sleeping position and physique, so we hope you will find it useful. "What height should I choose?" Tips for choosing the height of your Brain Sleep pillow https://brain-sleep.com/news/magazine/bspillow-height/ Q: I want to cancel my purchase. What should I do? A. Please contact us using the inquiry form and include your order ID. Q: I would like to exchange a purchased item. What should I do? A. The Brain Sleep Pillow is a 3-layer pillow with 9 gradients that is designed to provide the perfect fit. The pillow's shape changes over time to fit the shape of your head, so we recommend using it for a certain period of time. Also, some customers may feel that the fit has become flat, but the Brain Sleep Pillow can easily be restored to its original plumpness. If you feel that the fit is not quite right, please refer to the article below for how to easily restore it when it starts to feel a little flat! What if your Brain Sleep Pillow is starting to wear out? Recommended maintenance techniques from our staff https://brain-sleep.com/news/magazine/bspillow_maintenance/For pillow exchanges, you can exchange the size of your pillow only if you have purchased the Brain Sleep Pillow (LOW, STANDARD, HIGH) within 30 days of receiving the product. We do not accept size exchanges for other products. In principle, exchanges are limited to one product per product. Please note that we cannot accept re-exchanges or returns after an exchange. If you would like to exchange the size, please contact us using the inquiry form. In that case, please fill in the [Order ID] field in the inquiry form and the [purchased size] and [requested exchange size] in the content field.