The Olympus leather sashiko thimble sits at the base of your finger and is used to push multiple stitches through the fabric. Adjustable elastic makes it fit most fingers.
Sashiko needles fit at the base of your finger and although they can be helpful, they aren't as necessary as thimbles for other stitching because you are not pushing the needle through with the end of your finger, you are pulling it after you have loaded the multiple stitches onto the needle.
