Revealing "Iron Core of Koa'ki Meiru" is a cost to activate this effect.
You can activate this effect once for each "Iron Core of Koa'ki Meiru" you draw during the Draw Phase.
If you control multiple copies of "Koa'ki Meiru Speeder" and you draw "Iron Core of Koa'ki Meiru" during your Draw Phase, you can activate the effect of both monsters in a Chain.