They are not lightweight like those composites. Those composites weigh around 180 grams usually, these weigh almost 500. The bottoms are quite heavy, the outsides are lightweight plastic/flexible so your foot can just slip out in a fall. The inside branch is a steel of some sort. They seem heavier than my regular fillis stirrups. They are not at all hard to recover, that is the key selling point of these stirrups besides just safety, how easy they are to ride in and recover because they hang beautifully. There is a tutorial you can watch on YouTube to see how they work. And quickly return “home” all the time. I think they have most of the weight in the bottom for this reason. And also the angle is very inviting for stirrup recovery. I do not think this is supposed to be a “light” stirrup and Free Jump does not seem to market it as one. I didn’t see any mention of it on their website or the video. Maybe Fritt is thinking of another stirrup or maybe they are just marketed wrong in some places, some retailers just mess things up.
People should at least look at them in person before deciding on an opinion of them, I think it’s nice companies are out there inventing stuff to improve safety and that actually has functionality for sport at the same time, that is why I am such a fan of my cool if pricey stirrups!