This is $15 less than the amazon price or anywhere else I can find, amazon has had some fairly decent (not great) prices for everything 10-20TB lately but the 18tb is the best value sweet spot.
I am not 100% certain but conversations elsewhere suggest even the 18's and 20's are NOT shingled/these should be conventional magnetic recording. (no idea on the 22, though I doubt anyone is buying it at those prices) One person suggests a WD180EMFZ was in theirs, i dont know how to look this up. If anyone else can chime in please do.