Flexi-Post Internal Wrench, fitting post sizes 00 - 3. Crafted with a durable design. Facilitates the insertion of dental posts. Offers enhanced grip stability. Specially designed for use with the Flexi-Post system. Flexi-Post Internal Wrench is a handy dental tool developed for the Flexi-Post system. The wrench features a textured handle that provides grip stability during the insertion of posts.Built with a solid construction, Flexi-Post Internal Wrench fits post sizes from # 00 to # 3.