WheelchairDriver

Size 608 2RS is 8-22-7 (mm) (the way US write it)... your links list the numbers in different order but I think they are the same. The colored seals I think are still rubber seals not metal shielded with look like shiny metal. The Stainless Steel you'll have to translate.

stainless steel = acero inoxidable

Stainless steel is what it says.
Its Steel, to which chromium and molebdnium have been added in small quantities. It makes, rust and corrosion prone steel, inert in most situations. No rust.

If you were to throw a clean non painted steel bearing, or lump of steel sheet, or steel bolt or screw into the garden, it would be rusty in a week, solid rust, red and destroyed 1 year later.

If you throw a bit of quality stainless steel, or stainless steel sheet, or stainless steel bolt, into your garden, then 5 years later, after you cleaned off dirt and bugs, the stainless steel would be exactly as good as new. And still shiny.

This is whay kills most wheelchair bearings. This is a typical corroded STEEL bearing. Rubber seal has been removed here:
STAINLESS STEEL, or INOX bearings do not corrode if water gets in, and it does!

This used to be silver, shiny, with clear/yellow grease.
The brown is because water has got into it, as it always does on caster wheels and caster barrels!

This will not corrode. Even if you left it outdoors for years in the rain, with the rubber seal removed... It will look exactly the same after a clean with a cloth.

Today I downloaded the files from my camera.
There are a new old photographs.

608RS