The rubber rings in the book are listed by the outer diameter (OD) in mm. When purchasing on firemountaingems.com, they are listed by the first listed measurement. Type rubber rings in the product search to find the rings.

bluebuddhaboutique.com and metaldesignz.com will soon carry all the sizes of rubber rings needed for every project in Link It!

If you buy rubber rings from a chain mail site use the following guidelines:
5/16inch, 16g = 12mm
1/4inch, 16g = 10mm
7/64inch, 20g = 4.8(5)mm

Firemountaingems.com now list the 4.8mm as 5mm. They are the same.

Rubber O-Rings
Number of Projects using the following sizes.

15mm – 14 projects
12mm – 12 projects
10mm – 2 projects
9mm – 3 projects
7mm – 21 projects
4.8-5mm – 4 projects

Anodized Aluminum Jump Rings
Number of projects using the following sizes.

5/32inch, 18g – 2 projects
1/4inch, 16g – 7 projects
1/4 inch, 14g – 1 project
3/16inch, 16g – 14 projects
3/16inch, 18g – 6 projects
3/8inch, 16g – 1 project
3/8inch, 14g – 3 projects