I have some version of a SunRace 10-speed chain, and I'm curious as to why it seems as though each pin is a regular "non-hollow" pin, and a single one on the chain is hollow. Is this some kind of a master link? I couldn't tell via - How can I tell if a chain has a master link?.
Its not a master link - that's probably the one-use pin that was used to close the chain the first time.
This is what a Shimano pin looks like after its been snapped off. There's a clear difference to show this pin should not be pushed out again because the plate holes will be enlarged slightly.
Your one doesn't look quite the same - it does look like a snapped off line exists though. This was probably a hollow connection pin rather than the solid one supplied with that chain, or perhaps sunrace pins are all hollow.