The Weber Summit S-660 is one of the few stainless steel grills in the Weber Summit Series. The S-660 offers 6 stainless steel burners, whereas the Weber Summit S-400 grills only offer 4 stainless steel burners. The S-660 is very similar to the S-600 models, with only a few slight differences. It too offers a limited warranty and a Weber cookbook, along with a long list of impressive features making it a must-have grill. Some of these features include a 60,000 BTU-per-hour input, a 12,000 BTU-per-hour input flush-mounted side burner, an 8,000 BTU-per-hour smoker burner and stainless steel smoker box, a 10,600 BTU-per-hour infrared rear-mounted rotisserie burner, a Tuck-Away™ rotisserie system with flip-up motor and separate spit and fork storage in the enclosed cart, and many other features.