The stirrup bow is made of aluminum, while the opening arm is made of a special polyamide material. The stirrup pad is made of polyamide, too, and the tread is fabricated from stainless steel. The “AluPro” model, in principle, provides the same safety function as the Arena “HiFlex”, but it is based on different materials.
Unique, stress-actuated locking and release mechanism located between the lower end of the outer, pivoting stirrup arm and the foot support plate/tread
Easy and reliable “one-click” re-engagement of the stirrup locking and release mechanism once triggered.
SPECIAL SPRING EFFECT
Due to its design and construction which is based on flexible polymers, the stirrup conveys a less rigid and much more comfortable feeling to the rider than with conventional products
The springing stirrup bow and foot support assembly is capable of effectively absorbing and compensating for short-term and sudden impacts exerted through the rider’s weight from the top, e. g. during posting, jumping or hacking
Considerable benefits for the rider: strong relief of foot bottoms, ankles, knees and hips
Therefore, also very interesting for riders suffering from orthopedic problems.
I like the feel of the stirrups and they don't bother my ankles/knees. I was worried at first that my foot would accidentally slide over and open it up, but that is not the case at all. The irons are nice and light. as well.
The only "bad" thing I can say is that they do seem to have sharp edges so that when you roll your stirrups up, they do scratch your saddle. I just keep my stirrup covers on them till the last minute then pull them down right away. The scratches come out easily.
These are great safety stirrups. I purchased a pair for my jumping saddle last year and got these to put on my dressage saddle. Not only do they provide a higher level of safety, my foot sits softly in the stirrup without sliding - good grip on the sole of my boot. Highly recommend these stirrups.