www.sog-knives.net The SOG Fusion Seal Revolver knife, model FX-21, has a blade that can be rotated around the hinge. One side of the blade is a partially serrated knife while the other side is a full blown coarse tooth saw. The blade is made of 440A stainless steel with a hardcased black TiNi coating. A button is integrated into the glass reinforced handle that holds and releases the blade. A sturdy sheath is included for easy carrying.