Features a laser-etched, black metal ruler attached to the EndoRing II. Ruler’s black color reduces head lamp glare while operating with surgical telescopes. HD (high-density) foam is specially designed with a higher shear strength than EdgeEndo's regular e-Foam; it helps minimize the tearing of the foam while the rotary file is in motion and being inserted into the foam. HD foam inserts also aid in efficiently removing dentin and pulpal debris.