That would be the front skid shock as the rear shock will not have any spring on it.
The Puma is an entry level sled and the shocks are usually not rebuildable unless they have been replaced.
You need a RydeFX gas shock as a replacement for the hydrolic shock that it has.
This is the part # to cross reference for the rear shock, 0604-737 .
http://arcticcat.arinet.com/Empartwe...t&partner=ARCC