All that means is Shimano Index system. Meaning nothing more than the chainring spacing is compatible with index shifters. The crankset you chose would work with most 5,6,7,8, speed systems indexed or not. the important thing is using the proper Bottom bracket.
If you are replacing an existing crankset it may or may not use the same length spindle. Without knowing the model # of the crank you want on Ebay you will not know what BB to use, You also need to know what you have now for a BB length
There are two kinds of people in the world, "Those who help themselves to people, and those who help people!"
It would be nice to know what type and how old your bike is. In general just like the one you found on ebay,would say in the specs SiS compatible.
a Double or triple crankset made in the last 25 years would be compatible with indexed shifters. Shimano has always used their own terms for the systems they make and claim work together as a "system" for fine results so to speak. Like the terms M-system, Sti. to name some others. Some manufacturers may simple say Shimano compatible. Shimano is the biggest player in the game. worldwide selling 5 times more components than Sram and campognolo combined. So impressive that without even realizing it people look more at component levels when deciding on bang for the buck on a bike and the actual brand of the bike takes a second place.
SO tell us what you are working on and we can better help guide you along! and welcome to bicycleTutor
There are two kinds of people in the world, "Those who help themselves to people, and those who help people!"
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