Korg LP350 Digital Piano has a common problem called "squeaky pedals". Because of the inadequate pedals box support, the pedals and the bridge that holds them will eventually start producing a creaking sound each time a pedal is pressed.
This support is slipped underneath the pedals, as shown in the picture, and the four teeth on the sides will hold it firmly in place. This will successfully eliminate the squeaking.
The support is built for a bridge and a pedal box that are 19-20mm above the floor. It could be used also for some other models of electric pianos, if you stretch the object to a required height.
PLA will be quite enough.