Produced 1997 to present. Has top loading griddle. Has catalytic combustor.
Produced 2000 to 2005. No catalytic combustor. No top loading
Produced December 1994 to March 1998. Single pane glass and front access for the catalytic combustor.
Produced April 1990 to December 1994. From 1990 to 6-92 the doors had double glass in each door. After 7-92 had single pane glass in each door & catalytic access from inside the stove.
Produced July 1987 to March 1990. Catalytic access from the back of the stove & Double pane glass. Geisser testing label.
Produced July 1982 to June 1988. Has no catalytic.