Nexgrill XH-300A-3310 Assembly And Operating Instructions Manual page 19

Tighten all bolts and nuts on the cart, the firebox and the side shelves now.
Step 15
Place the flame diffusers
-
(part 10) (3 pcs) over the Burners.
19
Step 14
- Place the side burner grate
(part 28) in mounting
holes on the surface of
side burner bottom.