Not sure what you mean. Do you mean "if it is used" as opposed to "if it is new" or "if it is not used?"
If you're asking whether it's possible to transfer ownership of the actual device, the answer is probably yes, but it would take some technical knowledge to erase the information from the first owner and reset it for the second owner.
If you're just asking how well it works-- it's better than most regular pedometers. There are fancy running computers that are better than the Spark device, but they cost at least 2-3 times as much. I would say the little Spark thing is about the most accuracy you can get for the money.
Fitness Minutes: (15,905)
9,717 3/3/14 3:35 P
Of course it does. :) What do you mean by work, exactly? It counts steps, if that's what you mean.