5mm (3/16") inside diameter / 10mm (3/8") outside diameter / 3mm Gap (after install) / 10 pack
11mm (7/16") inside diameter / 22mm (7/8") outside diameter / 3mm Gap (after install) / 4 pack
17mm (11/16") inside diameter / 30mm (1-3/16") outside diameter / 5mm Gap (after install) / 4 pack
Pls search for "Snap Together Grommet Demo" on YouTub for installing instruction.
Require a light weight hammer to push them together. Please make sure to cover the snap with towel before hammer to avoid scratches on the metal rings.