F1 SAMPLES 3 IN X 3 IN- 1/2 IN, 1/4 IN, 1/8 IN THICKNESS Includes 3 inch x 3 inch squares of 3 different thicknesses Made of minimum 95% off-white wool Best for applications where unusual strength and hardness are required Has a density of 0.32-0.36 g/cm3 Includes 3 inch x 3 inch squares of 3 different thicknesses