The lower grill has two welded tabs and two rotating tabs. The upper grill has matching notches. With the two grills laying flat and open, slide the smooth longer end of the upper grill into the desired hole in the welded tab of the lower grill. (Lower holes are recommended for hot dogs, brats, hamburger, etc. and upper holes for chicken and thicker meats.) Place your food on the lower grill and sandwich the food by folding the upper grill over. For successful chicken flip, properly weight the grill toward the rods that extend out of the grills. Slide the locking tab over the ends of the upper grill to secure the food. Place the grill into the notches of the assembled grill side panels. Periodically flip the grill.