It's a bit odd they didn't include this bag in the first place as the packaged version is really not what I'd expect from Snow Peak. It's like placing a gallon of milk in a plastic bag. All the heavy canvas bags are quite rugged so I ordered this to actually work with the fireplace. The fireplace itself probably doesn't actually need protection; it's everything else you are protecting from damage and the inevitable collection of ash and cooking residue.
Given the odd shape of the fireplace, there's not a lot of storage options. I fit the grill bridge and half grill in the bag for my medium with room to spare. It's still held closed with a simple cloth strap and I kind of wish it were able to be zippered shut, but overall I feel it's a needed add-on that works well and should last.
This review was written in the old system and had content requirements that are different than reviews written today.