The Weber Summit S-640 is a gas grill constructed from a stainless steel cart with a stainless steel bottom shelf and a stainless steel shroud. An upgrade from the Summit S-620, the S-640 ditches its predecessor’s 12,000 BTU per hour input flush-mounted side burner, but features 6 stainless steel burners that burn at up to 60,000 BTU hour, a smoker burner and stainless steel smoker box that burns at 8,000 BTU hour, and an infrared rear-mounted rotisserie burner that burns at 10,600 BTU hour.