1/4" angled ruby tipped blade. Very small nick.  Only seen under high power jewler glass.
These are no longer made and are highly sought after - This blade works great. 

These Ruby Blades are the cadilac of swivel knife blades. that is really a ruby on the tip.  Cuts like a samuri sword slicing butter.  No more sharpening or stropping!  Never need sharpening.  

Must work to protect the blade.  Though they are tough, they chip when dropped on the floor.  Never used a ruby?  Gotta try one and get rid of the rest.