The SKF sealing category covers parts that work at very different points in a machine. Radial shaft seals run on rotating shafts, while hydraulic seals belong to cylinder assemblies. V-rings, sealing washers and Speedi-Sleeve wear sleeves have lines of their own. Before you compare sizes, identify which surface is being sealed and how the part is mounted.
On a replacement job, the part number and a look at the assembly support each other. A sleeve that restores the shaft's running surface is not the same item as the seal that runs on it, and rings that look alike can do different jobs. Note the order of the parts as you take them apart, and photograph the housing as well as the part you removed.
Send the full designation, the quantity and dimensions taken from the actual part or the drawing, and say where each measurement came from. Add the application, whether a shaft or a rod is moving, and the fluid, if you know it. When the marking does not identify the design, photos of the profile and both faces point the search to the right line; color alone does not tell you the material.