I thought that it would be better to use a corrugated cardboard opener rather than use it. Thanks to jaggedness it is easy to cut out what escapes like a hose. Either way it is difficult for power to enter or whether the edge of the blade is bad, hard one can not cut unless you put strength in both hands. It was a bit disappointing because I thought that it was a better thing to look at the product description of the manufacturer. Also, the color was green rather than black.