yes they do. i assume they are called COMFORT ZONE 15 ft...
seat is for young person.leaning against tree is not good with your back.
you can buy optional side rails, but my wal-mart stadium seat idea is better.without side rails it feels like you are going to fall off sides.
i am older and need comfort.stadium seat and my platform upgrade helps.
but better idea is buy a strap on sling type seat and put it above the seat secured on tree then use the ladderstand seat for your feet.

no way i can sit all day in comfort zone treestand........i saw sling type seat ,a steel one at dicks for around 69 dollars but they gone.that is way to go.

in fact i have summit climber i use for archery but i am going to use the top seat section with my dicks ladderstand in gun season.my feet will be on the seat platform of dicks stand where you sit.
this way i dont have to climb stand in dark in morning at 20 degrees in gun season and will have seat that i can sit in all day........

take care sproul