I replaced the pedals because they aren't very good. They're intended to be used with toe cages, so the side that hangs up by default isn't flat (though it's perfectly usable). Furthermore, one of the bearings on the right pedal is clearly worn, since if you put too much force on it it sometimes clicks every revolution.

They are 9/16", which is pretty standard. Outer rim is metal, inside is plastic.

Anyhow, these will be perfect if you want some functional pedals for as cheap as possible.