I am curious what model this is?

It is the model with the loop handle.Not the new and bigger uno,which is a dog,but the little green Optima (431BX).

How does this model work on hardwood floors?
Does it lie down and go under beds, etc.?
How easy are the onboard attachments....
When vacuuming stairs, how do you use this unit?
You have my curiousity peaked. I love that it is only 11 lbs.

This model is just fantastic on bare floors as well as carpeted surfaces.Onboard tools include an edger and an upholstery brush.The only drawback to the tool use is that the dial to switch from floor mode to tool mode is located on the bottom of the unit instead of the handle.For me,it's not a problem,but for someone who is overweight it could be a real drawback.Although Eureka actually has models that lay down and fit under beds,this is not one of them.The profile is almost a fit though,and sometimes it does fit under real high bedframes.The head of the vaccuum is small,and because the tank doesn't startat the bottom,there is room to go under the counters to the wall,a huge plus.This is something that can't be done with a Dyson.For stair cleaning I usually use the upholstery tool,but if they are wide,the entire vacuum can be used.

Cupajoe- I have the same model Eureka Optima 431BX as well as the same problem of the wheels falling off. I'd like to repair them. I assume hole was drilled in center of wheel & hub. What size & length bolts were used? Thanks