I added an extra damper on the lid of my 14.5" WSM to get more airflow and higher temps. I order the damper from Ereplacementparts.com. The damper for the 18.5" WSM is the same size as the damper on my 14.5"WSM. Three dampers come in the kit. once the holes are drilled the new damper just screws in place. My first cook was beercan chicken with no water pan. For charcoal I used the new Kingsford lump briquettes. The temps started out too hot (450deg) but I was able to lower it to 400. It maintained high temps for the 1hr 30 min cook and the chicken was good even the skin.