Wiper blade refills
Ok. I called Anco (still using the name but it's a Trico company).
The customer support was good.
Your 18" is no longer in production as just a rubber refill, the term that we knew from years ago.
-Their term, "refill" comes with the "painted silver metallic" housing AND rubber blade.
-The term ARM is the part that goes to the wiper transmission.
So, Trico # 33183. The last digit denotes that this 18" blade is for a 3/16" side pin mount.
Napa# 61833 is the same exact product, made with Napa's number.