I bought two perches with bolsters.  I was going to put them in the shed for my new kitten but they're too nice so they're both in the house for my adult cat. She really likes them. The bolster gives her a good way to look out the window and rest her front legs.  I have an old farm house with plaster walls so I just set the perches on a small table just below the windows so I don't use the braces underneath.