The resistance value, which is a scientific measure of heat flow, is known as the "R" rating, the higher the R-rating, the better the fat batt performance. A complete range of R-rated fat batts are available to suit the climate you live in as recommended in the Australian Standard AS2627.1 for all areas of Australia. Your local fat batt distributor will advise you of the recommended R-rating for your area. Fat batts are manufactured from pure glass and are guaranteed for the life of your home.They require no maintenance, are rot resistant,and do not sustain vermin