The inside circumference is about 8 1/2" (191 mm) making is a medium to large size. There is no clasp or toggle to get in the way. Everything is technically waterproof but long term immersion is not recommended.
A similar design was posted back in November and is available in the fiber wrapped jewelry section of the ArtFire venue.
Find this item now listed in the Etsy shop.
Custom sizes and colors can be requested from the Etsy shop. Click here to go the shop page then click on "request custom item" from the menu on the left margin.
design and photographs © copyright 2011 WhatKnotShop