When this product came in the mail, I wasn't sure it was the right cover. Seemed small. But we stretched it over the two 30 lb tanks, and it's tight, but it fits great! There is a heavy cardboard insert that fits into the top panel of the cover, and it has a flexible strip in the center so I can be inserted easily. I would suggest inserting the cardboard BEFORE putting the cover over the tanks. We didn't, and it was a struggle to get the cardboard into the top.The material is a heavy vinyl and tSee full review