Wire Mesh Vent Screen (R-300) by JCJ®. Pack of 3. For Norcold Vent Opening Measuring 20" Length. The R300 fits Norcold refrigerator vents. This product is made of high-quality materials to serve you for years to come. Designed using state-of-the-art technology and with customers in mind. It will meet your needs and deliver great quality at an affordable cost.