Rubber grommets are protective rings inserted into holes in panels, metal sheets, or chassis to protect cables, wires, and pipes from sharp, unfinished edges. They are primarily used in automotive, electronics, and construction industries to prevent abrasion, seal out dust and moisture, reduce vibration.Custom rubber grommets are usually made using natural rubber, nitrile rubber, EPDM, silicone, and neoprene materials. Each rubber type has its own strength and limits.