What chain for Shimano RSX chainset?

g_m Posts: 8
edited February 2010 in Workshop
The chain needs replacing on my bike, which is equipped with a 21 speed Shimano RSX chainset. I don't recognise any of the markings on the original chain as being similar to anything currently available online. In a hurry I bought a Shimano HG70 chain as a replacement, because it is quoted as being suitable for 6/7/8 speed cassettes. I just wondered if there is anything which is better suited for the job.