These trimming tools are for smoothing the bottoms of plates, or anything else where you have a large, flat surface which you want smooth. Unlike the traditional metal rib, it's easy to grip the handle of these scrapers and avoid cutting your hands.
The 2" scraper is good for bowls and smoothing out wire cutoff lines for most ware. The 3" scraper is good for plates and really large bowls.
Like most of my trimming tools, made from steel strapping recycled from Southern Oregon lumber mills.
The 3" scraper is currently out of stock, contact me to be notified when I have more.