it has an elastic back for a more flexible fit. if you have a larger home, you may find that you need to empty the dust container almost every time you clean, and wash the filters more regularly. at the same time, the grounds, the pool and the restaurants were never “full”, but very quiet and pleasant. after three weeks away, i am finally back! what are your counter arguments when faced with this? as for the horses, they have been up in their “happy horse-y valleys” grazing to their hearts content. when we get together we are constantly evaluating, trying to review these things. 