Shimano 9 and 10 speed cogs

[93legendti]

Are Shimano's 9 and 10 speed individual cogs the same width, with the spacers being narrower on 10 speed cassettes? Or are the 10 speed cogs narrower than the 9 speed cogs?
Thanks.

[torquer]

Sheldon Brown provides the answer (from the afterlife, no less):

http://sheldonbrown.com/k7.html#spacing

Looks like both cogs and spacers are different.

[93legendti]

Thanks!