This is the newly redesigned burn grate (released 2019). It is reinforced with several crimps in the metal which prevent warping from heat.
The hole pattern has also been altered for better air flow, resulting in more efficient direct heat and better consistency across the cooking chamber.
This grate fits all YS Series pellet grills (YS480, YS640, or YS1500) (new or old), and can be used with or without the new ceramic igniter.