5/8" x 1-1/8" x 5/16" x 1/16" Black Rubber Grommets GRMTR-109 (8 pcs.)

Diameter: 5/8"
Diameter 2: 1-1/8"
Thickness: 5/16"
Material: Rubber
Finish: Black
Type: Grommet
Groove: 1/16"
GrooveDiameter: 7/8"
Groove: x 7/8"

Box of 8.

Grommets and eyelets are metal, plastic, or rubber rings that are inserted into a hole made through another material. They may be used to reinforce the hole, to shield something from the sharp edges of the hole, or both.