Relyx Fiber Post drill, Size 1, 1.3 mm Diameter, Yellow. Single drill. RelyX Fiber Post Drill uses its unique resin formula and equally dispersed parallel fibers to show immense mechanical strength. The microporous surface improves the post's strength with micro-retentive effects. With an elasticity comparable to human dentin, RelyX lessens the chances of root fracture caused by the wedge effect. The drill has an outstanding radiopacity and light translucency to guarantee efficient deep light-curing into the root canal.