B&P Lamp 3" X 12" Chimney, 3/4 Frost 3 inch by 12 inch height and 3 5/8 inch bulge 3/4 frosted chimney for #2 burners and 3 inch galleries Borosilicate Glass Heat Resistant All glass chimneys will vary in thickness due to the manufacturing process. They will fit the holder/burner specified in their description.