Cast Iron Damper--5 inch
A good quality damper is required for your stove to burn its best.
Having a damper means you can control your fire, burn more efficiently and use less wood over time.
You'll have this damper for years--it's the one I've been recommending for a long time, now.
Cast iron, solid construction. Get a pre-drilled riser for this damper, to save yourself some time.
Also comes in a 4 inch size, if that is what you need.