This smoker has 1" insulation board to insure internal smokehouse temperatures of 160-170 degrees plus in 5 degree weather. 1000 watt heating element gives you internal temperatures from 130-220 degrees with the unit loaded. Inside dimensions 15" deep x 20" high x 16 1/2" wide. Comes with 4 shelves, 3 dowels, thermometer, stainless steel sawdust pan, instructions, and the stand. There is an additional $24.00 shipping charge on this item, it ships UPS oversize 2.