Have a 30 inch which does a fabulous job but wanted to smoke more summer sausage and beef sticks at one time. Glad I did the 40 inch has controls up front and a window to check on meat without opening door. Really like the wheels to allow easy movement of smoker. Plenty of room to hang links, sticks and ring bologna. Built in prob works great to monitor meat. The racks and slides are very sturdy to accompany the well built smoker it’s self. Always makes fabulous tasting smoked meats. Bottom line great smoker with great features.