Very good product and sturdy foot pedal that stands stable on the ground with rubber feet.
The manual of a Yamaha PSR E423 says that you can use an fc4a or an fc5a foot pedal, but I chose this fc4a because it looks just like a (right) pedal of a real piano.
Box shipping from Coolblue is much larger than necessary.
I had connected the foot pedal to my keyboard before first use and as always the power button on my keyboard is pressed and I just plug in the adapter to play the piano right away but the result is that the sustain is counterproductive if you release the foot pedal.
So if you want to get the action of a real piano with a sustain pedal that you want to press with your foot and stop the drooping tone of a pressed piano key by taking your foot off the pedal, then you have to press the power button on your keyboard. power ON AFTER plugging in the adapter.
So I'm going to have to change my old habit and turn off the power button after each use of the keyboard and press it again on new use, if I want the sustain to work normally when pressing the pedal.