GC Fiber Post Drill Refill Size 1.4Prevents root fractures Prevents debris formation Available in three diameters to suit various techniques Precisely drills into the tooth preparation GC Fiber Post Drills are handy dental tools that cut into the dentin without fracturing the root or producing debris. Available in 1. 2 , 1. 4 , and 1. 6 mm diameters, these drills guarantee accuracy, speed, and reliability for various restorative techniques.