I was trained by Roxanne( daughter now owns the company) how to size the customer. She sized me . Your finger changes sizes daily and it is great to have two different sizes but that is a lot of money for most people to spend on a quality thimble. I personally bought ever inexpensive thimble on the market until I bought Roxanne. If you contact the company She may allow you to return it for the next size down. Is it possible the shop would allow you to get a different size. I often suggest the customer use it for a couple days and if needed change the size. What size do you have. I have a 5 had a 4.5 for a while but sold it now when my finger changes for a I will stick a little ball of of masking tape down inside this is not needed for a very long time frame usually works great.