Aprilaire 10 Water Panel 2 Pack for Humidifier Models 110, 220, 500, 550, 558

I have Aprilair model 550. Does it come in quantity of 2 for $17.20?

Which side up for water filter in alpilare 550

this says eligible for free shipping. But when I go to check out with a total order over $100.00 it wants to charge me $7.17 shipping for this item

I need Skuttle model 2001 # A04-1725-051 water panel filter for humidifier on my York furnace? Is this the item I need?