NILOS rings 21304 AV from Nilos are ideal for sealing spherical roller bearings with an inner diameter of 20 mm, an outer diameter of 44.8 mm, and a width of 2 mm. They weigh only 0.004 kg, making them a lightweight yet robust option. Made from electrolytically zinc-plated special band steel and with an externally sealing design, these rings provide reliable sealing for various applications.