UnoDent Diamond Burs Cylinder FG No.542 Medium 109-015M (835) Made with the finest Swiss-made steel shanks. Extensive range of shapes in all the most popular sizes. Triton™ bonded to double the strength of diamond adhesion and improve performance. Up to four grit sizes for all uses. 542 Diamond Burs FG (Friction Grip) Medium Grit Burs - Cylinder.