I purchased these to replace the plastic fold-up pedals on a Dahon 6-speed. One of the original pedal bearings busted. I bike just a couple miles everyday in downtown LA so while its not very far for very long, the street conditions and stop & go give the pedals a lot of stress. So far these feel very strong in comparison and I expect them to last a long time.
The blue button unlocks the hinge and the pedal frame folds down leaving the flat center and button in place. This is nice since you can still pedal or stand on one side and coast while the pedals are folded. This is different than many other fold-able pedals that hinge at the center and don't leave a flat place for your foot. They fold back in a snap.
So while these ran a bit more expensive than all the other options available to order online, I feel they were a good investment and will outlast the plastic/nylon pedals.