Diffuser and grill zone cover not included, both come standard with your Platinum grill.
If you want to slow smoke a tri-tip then finish it off with a nice sear then you will want the quick grill zone kit. All Kuma Platinum grills come standard with a removeable grilling zone cover but this accessory turns your grilling zone into a "quick grilling zone". The quick grill zone kit allows you to activate your grilling zone with the simple slide of a handle any time during your cook. The kit comes with a pair of stainless steel slides that attach to your diffuser along with a stainless steel control rod and handle.