Flexi-Post Stainless Steel - Introductory Kit10 Serrated Posts, 1 Primary Reamer, 1 Secondary Drill, 1 Extender, 2 Wrenches, 1 Gauge. Color Yellow has 2 Reamers and no Secondary Drill. Through the incorporation of the patented split shank, the stresses of insertion are absorbed by the post (not the root) during placement. Flexi Post predictably provides maximum retention with minimal stress!