I bought the side box and, as per instructions, hammered out the side panel on my charcoal grill first. All went well, a pliers straightened out any warpage. Then I went to do the same to the side fire box. In progression from small hammer to two-handed sledge, the knockout never knocked out and I ruined the entire box. I called Char-Griller, left my # etc. and, after 5 hours with no reply, took everything back to Lowes. They took it back with no questions and I came home with another one. Before I could unbox it and try to drill it at the spot welds, Char-Griller called. Said if I had any trouble at all just fax a copy of the receipt, my name and address and the problem...they would mail me a replacement. Very nice. Some of the units, made in China, have been welded too strongly and they are aware of it. Bad engineering decision; should have bolted the knockout unit on...could have used the same 6 holes the buyer has to punch out.