Dear Lilly,
Thank you for your message.
We have a size chart displayed on each product page.
Go to the product page, scroll down, the size chart is in the product description.
Please select the size that matches your own measurements.
Zaful offers a 30 day Warranty for all products. Please refer to our policy here: http://www.zaful.com/returns/
If any problem after receiveing your order, please email to support@zaful.com or submit a ticket here: https://support.zaful.com/ticket/ticket/index
Best Regards
Zaful Customer Service