This is the shelf for parts that do not sit neatly under one heading. Of the items here, most also belong to a proper category, and the links below lead to the fuller ranges.
Where to look instead
For the full ranges see lighting, reflectors, cables and connectors, brake shoes, wheel bearings, couplings and jockey wheels.
Why parts end up here
A part lands on this page when it fits several categories at once or none of them cleanly, such as a bearing kit sold for one specific axle, or a tester that serves both 7 and 13 pin. It is worth browsing if you know what the part does but not what it would be filed under.