This is the replacement Pellet Grill gasket that goes between the hopper burner assembly and the frame of the grill. This gasket has a couple of different important functions. First, to keep smoke and heat from escaping out of the grill. Thus, helping to maintain grill temperatures. Second, the gasket serves as an antivibration barrier, keeping damaging vibrations from the grills moving parts down to a minimum.

In the manual for the Oklahoma Joe's Rider DLX Pellet Grill 900 and 1200 models this is listed in the parts key as item #7.