This is NOT the 4/09 older/larger shingle gauge The 1/12 ( for shingles manufactured after Jan 2012) Shingle Gauge measures the thickness of 3-Tab shingles, and based on analyses made by Haag, correlates that thickness to a warranty range. The 1/12 Shingle Gauge is an estimating tool which provides users with a warranty range for 3-Tab Shingles. There are a small number of outlying shingles which do not conform to the gauge. Why does the 1/12 Shingle Gauge not include Laminated Shingles? In early 2011, most asphalt shingle manufacturers introduced lifetime limited warranties for their products. Haag responded by acquiring 76 models of these shingles from every U.S. manufacturer to measure shingle thicknesses and to compare against their warranties. The testing concluded laminated shingles could not be separated by thickness into warranty categories. The thicknesses of new lifetime warrantied shingles varied dramatically. Whats more, many manufacturers limit lifetime warranties to residential installations and use a year designation for commercial-use installations. Without a strong relationship between warranty and thickness, we cannot create an updated Gauge which includes Laminated Shingles. Is there any type of shingle the Shingle Gauge cannot measure? Yes. Any type of shingle (3-Tab or Laminated) made with modified asphalt (sometimes called impact resistant) does not conform to the 4/09 or the 1/12 Shingle Gauge. We also do not test T-Lock Shingles, and as mentioned, due to manufacturers warranty changes, the 01/12 Shingle Gauge can no longer measure Laminated (architectural) shingles.