The Macro-Lock™ Illusion™ X-RO® fiber post joins the line of RTD quartz fiber posts that have set new standards for retention, flexural strength, bond strength, esthetics, fiber-optic translucency, and atraumatic removal in just minutes. Unique to Macro-Lock Illusion X-RO are several macro-retentive features which include: circumferential grooves in the post parallel section to retain the core, two flat sides in the head design to prevent rotation of the core, and spiral grooves in the apical section of the post for an improved cement lock. These three features help make the Macro-Lock Illusion X-RO the most retentive post ever developed by RTD.