The Equalizer® Express® blade was developed from daily use on hundreds of different vehicles. The 3" is the most used size and is perfect for slicing through the wide urethane that is typical on newer vehicles. It works well in all places where you plunge cut or angle cut. The 1-1/2" blades are perfect for removing glass that is not broken. The narrow 1-1/2" blade is more flexible which puts less stress on the glass. On some vehicles the urethane is far below the glass, but there is a limited amount of vertical space inside the vehicle. In situation like this you will need a 12" blade (LBE-1402 or LBE-1403). They perform the same purpose as the BFE-1400 and BFE-1401, but are 2" long longer. On a few vehicles, specifically the Windstar, Transport, Camaro and Caravan, the urethane is very deep below the dash. This is also true on the Century Class Freightliners and some motor homes. For those vehicles you should keep one of the 14" blades in your tool box. All blades are made of a specially formulated steel that is hardened and then tempered using a cold molecular aligning process. This makes the blades very flexible. Each blade will easily remove over 50 windshields when used according to directions. Made in USA.