This sample bag of the F7 Industrial Felt gives you a 3 inch x 3inch square each of 1/2 inch, 1/4inch, and 1/8inch thickness. SAE F-7 Felt is made of minimum 80% gray wool and has a density of 0.25-0.27 g/cm3. F-7 is recommended for dust shields, wipers, grease retainer washers, wicks, vibration absorption and other uses where resilient felt is needed. The sample bag is a perfect way to match and select your grade of felt and be able to physically feel the felt. These can be kept in your swatch library to refer back to or for applications that need a smaller amount of industrial felt to work with.