I think they're all ladders the fold. I put this on in a few weeks ago:
http://www.lowes.com/lowes/lkn?action=productDetail&productId=107006-287-S2208&lpage=none
My neighbor had done his the week before, saw mine and yanked his old one out to put in this type. Would have been nice to have some help but can be done solo without too much trouble.