The 2 1/2 Inch Closed-Back Grommet is a practical and versatile solution for recess mounting sealed units. It requires a 2 25/32 inch mounting hole and fits most Peterson 142, 143, 162, 163, and 172 series lights. Sold individually, this grommet allows for the installation of incandescent lights with the 142-49 or 162-49 plug, making it a convenient and efficient choice for various lighting applications. Its closed-back design ensures a secure and professional-looking installation, making it an essential accessory for any lighting project.