What part of the rear wheel is this? Fell off while taking wheel off.

[b00stin4days]

Taking my rear tire off to get a new one put on and as I was just about to pull the rear tire off, this piece fell and I didn't see where it came from. Not sure how to put it back or which way it should go, can anyone help me out please

http://imgur.com/WpYWBKY
http://imgur.com/dicKpty
http://imgur.com/dn0TbzI

[Suzuki Stevo]

Looks like #5, SPACER, REAR AXLE RH  http://www.mrcycles.com/oemparts/a/suz/506b32b8f870022ba8af9abb/rear-wheel

[b00stin4days]

Thank you! Yes it is.