Note there are many generic bags available on-line that are cheaper but these are specifically tested to be safe for cooking food in and are embossed with a food safe logo on the edges of the bags.  

Each box contains two rolls, one larger than the other.  The bags can be cut to the required size and sealed.  If smaller bags are required I make these by cutting a length from the large roll, sealing one end, then cutting straight down the middle along the clear centre strip and sealing these edges.  You will then have two small bags suitable for freezing herbs etc.