i think these have been on the market for a few years. in america though i think. i looked at a lot of reviews before i purchased them.
The bow i supposed to help you retrieve your stirrup easily if you loose it, due to the way the bow sits when in a stirrup leather.
My picture are probably not very good. i think when you are riding in them and when attached to a leather they would look more even.
I have pain in my knee and riding makes it more painful so i am willing to try anything that can make it less painful and more enjoyable. I suppose though what suits one person might not have the same effect for another. I guess you have to do a bit of trial and error with new prodcuts.
If you go to www.thesaddleryshop.co.uk
(i think) you can actually hire them and try them out. Then if you feel they make a difference you purchase a new pair and send the trial ones back.