All CRL BTB Long Blade is used to cut urethane deep below the dash line. Unique to the BTB Tool is that you can perform the removal from the exterior of the vehicle and still reach to the bottom center of most windshields. They are made of spring steel, and can be re-sharpened to ensure constant clean cuts and extended blade life. 1-1/2" (38 mm) of the overall blade length is encased in the tool holder.