They may be used to prevent tearing or abrasion of the pierced material or protection from abrasion of the insulation on the wire, cable, line being routed through the penetration, and to cover sharp edges of the piercing, or all of the above. Features. Grooved Rubber Grommet. Made with high quality materialSpecifications. Length 3.85 in / 9.78 cm. Width 5.4 in / 13.72 cm. Height 0.7 in / 1.78 cm