Electric Earth said:These are plastic of some sort, but seem to have a good rating after lots of reviews. They might be a good value.
"Polyamide" is nylon made by someone other than DuPont. Nylon pedals are, generally speaking, cheap junk. Polycarbonate pedals can look almost identical to nylon pedals, and can be almost as cheap to buy, but hold up much better in the long run.
Odyssey Twisted PC are very common and inexpensive polycarbonate pedals that are proven to be as trouble-free as anything on the market. They come in lots of different colors if that's your thing. Mostly I sell black ones.
Glass fiber filler makes nylon into a much more robust material, so if there's a lot of glass filler in the above linked pedals, they might be just fine.