Yes, the impeller in case your pump breaks one. That's the most common failure in a pump, that and depending on the type of pump, an impeller housing. Mag Drive pumps commonly have impeller shafts break and housings - both are easily available to replace.
Poly filter pads should be available from your LFS or wherever you buy your supplies. It's a polyester pad treated with adsorption resins that remove toxins. Looks like this:
HTH
Jenn
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Member of the "J" Crowd & the BRW Crowd!
LFS Owner:
Imagine Ocean

Just keep skimming, just keep skimming, just keep skimming, skimming skimming! What do we do? We skim, skim, skim!