- Use the Big Apical Files STERILE when preparing root canals larger (than size 30) apical diameters or as a complement to the S1 Plus File or S5 Rotary Files STERILE. - Shape the canal as usual with the S1 System or S5 Rotary System and simply finish the apical portion using the Big Apical Files STERILE. - Use them according the instructions for use accompanying the S1 Contra-angle handpiece or the S5 Endo Motor. - Big Apical Files STERILE come in pre-sterilized packages – ready to use straight from the box. **For further product information, please contact Chat Support**