Tines of D-ring are curved inwards to fix matrix on a distal side of the tooth. High-Quality Stainless Steel Clamp with Flat Tines to be used with Forceps WARNING!!! When operating with ring: 1) make sure of the integrity of the ring and absence of rust on it. 2) avoid high-speed opening; 3) open the ring for not more than 10 - 12 mm width. 4) open the ring for necessary width outside the mouth before placing it on a tooth. CLEANING AND STERILISATION INSTRUCTIONS Recommended to use Dry-heat sterilization process 1) Submerge instruments in cleaning agent solution with neutral pH for 20 min. 2) Rinse the instruments thoroughly with purified water for 3-5 min. 3) Perform standard moist heat/steam sterilization procedure following the sterilizer instructions WARNING!!! 1) Do not use cleaning agents with a high percentage of chlorine and cleaners containing oxalic acid. 2) Do not keep instruments in liquid medium for more than 3 hours.