We have had the same Polaris for about 8 years with no issues. I'm not
sure of the model, other than it's blue, connects to the jet only, and
has a mesh bag on top that you just have to empty every now and again.
I looked at the website and believe it is the 180. It requires its own
small pump near the filter, but it's a great deal.

I have it on a timer so that I just leave it hooked in to the jet all
day and night, and then around dark, it comes on and cleans the pool
all night. It cleans steps and despite being a master of how things
work, I cant figure out how it works with no power.

Like I said, it uses no electricity and yet somehow it keeps track of
every inch of the pool. It also can come to the surface, like a
surfacing whale, and then get onto steps and even into the skimmer
entrance. Sometimes it gets stuck in the ladder but they make plastic
slats that block it from doing so.

I would recommend this one 10 fold. I use the pool as a target for BB
guns and it will easily pick up 100s of the relatively heavy BBs
quickly. It will pick up rocks, leaves, dead frogs, and even dirt
(How?!?!). Go to a pool store and ask about it.