The Clover® Thimble is designed to protect your finger from accidental pokes with hand needles. Natural Fit Medium- This leather thimble has no seams or stitches, allowing the needle to be pushed from any angle, is sewn 3-dimensionally to fit the shape of your finger and has 2 layers of leather for increased safety. Packaging has a hole/size guide. Inner diameter approximately 16mm(5/8 inch).