Love these irons! I didn't really know what to expect since the description is rather vague. They are hinged and flex at the footrest, allowing for a more comfortable and secure leg. I often lost my stirrup at the canter, but no more! My bum knees are much happier as well.
Bought these a couple of years ago after my third ankle surgery and I love them. I cannot stand to ride in regular stirrups because it kills my ankle but with these I can ride all day! They have held up well and will definitely be buying another pair for my new saddle.