Some manufacturers may claim that an insulation product offers remarkable insulating value. Any product that is promoted as offering a long-term thermal resistance exceeding RSI 1.14/25 mm (R-6.5/in.) may be making a claim that is not substantiated by industry-recognized tests to specific accepted standards. Also, be alert to any manufacturer's thermal performance claims that are based on building envelope systems (e.g. whole wall or ceiling configurations) that are not identical to those configurations or conditions in which the product is being considered for use.