GC America GC Fiber Post Assortment KitGC Fiber Post is composed of non corrosive, biocompatible substances that provide low elasticity and high flexural strength. The tapered design of the post reduces dentin removal. This radiopaque material resists fatigue, stress, and root fractures. The Assortment Kit contains the following: 5 x 1. 2 mm post, 5 x 1. 4 mm post, 5 x 1. 6 mm post, 1. 2 mm drill, 1. 4 mm drill, and 1. 6 mm drill.