Necklace is crafted with a box lock clasp so it isn’t adjustable to size. Perhaps you could take it to a jeweler to have a sized.

Absolutely :)) I purchased my Tennis Chain a year ago and have not taken it off. I wear it while showering and it continues to shine brightly. It has not tarnished or discolored at all. Although I have not swam with it on yet, I would like to think it would still glisten. The craftsmanship is sturdy. Highly recommended.