For Chainmaille: Works most often with 20g 1/8" jump rings . For its' size, this is a fairly thick O-Ring. Works great for European and Japanese weaves that have simple connections and require a low AR.
For leather: This size fits 2mm, 3mm and flat 3mm leather cord.
Other uses: These work really well as spacers to protect strung beads. These are also used as stitch markers for Knitting & Crochet and can also be used for Macrame. EPDM O-Rings were developed to form a waterproof seal. They can be used with LED lights to form a waterproof seal between the bulb and hardware. These have also been used for body piercings that often require a stopper, tattoo equipment,paint guns, bicycle & Industrial parts. O-Rings are also known as gaskets or waterproof seals.
Sizing:The ID or Inner Diameter is the size of the hole. Generally, choose an inner diamter slightly smaller than you require. The rubber will stretch to fit over items and form a strong seal or hold items in place.
The below table shows the AR average of a jump ring combined with this O-Ring size
