The Ripper TM serrated blades feature baked on, E-friendly, finish to protect the blade, while the serrations provide a faster, smoother cut. When combined with the D-Ice'r ARMOR TM on the bottom end of the drill assembly, the Ripper TM provides the best in super-fast cutting and resistance to ice up. #3540, 10" Ripper Blade, Replaces #1803 and #1803-D