Slow and Sear is the name of the grill insert. Not used as a reverse sear on butts, etc, just steaks, or quick cooks.. When using it for slow smoke, you only light some coals and let the rest catch slowly for a long cook, For searing a full load of coals is lit, when they are dumped into the chamber they are all in a high pile then and very hot for searing. For my 2 smokes so far I lit about a dozen coals in the corner. when ready then close to a unlit full chimney, maybe 3/4 fills the chamber for the long cook. Maintained 200-250 temp for 10+ hours without adding any coals, on a Maverick grill probe temp, with coals left to go if needed