For VEFANK ZD47*84*20 Axle Oil Seal Mechanical Seal with FKM Metal for Industrial Oil Resistance Loader Shaft Describe: The contents of an oil seal kit can vary by application, but generally include: Primary Oil Seals: Critical for preventing the leakage of oil from rotating shafts, hubs, or bearings, ensuring lubricant is contained within the assembly.Secondary Seals or O-rings: Provide an additional static seal between housings and components to prevent external contaminati