The patented Flexi-Flange is a "specific-use post" with a parallel-sided, threaded, split-shank design. Its scientifically designed countersunk flange is for cases lacking supportive coronal dentin, along with a second tier, which produces an intimate fit with optimum metal-to-dentin contact for maximum stability. Split-shank gradually collapses as the post is inserted into the canal, effectively reducing insertional stresses.