The construction of the Talley Lightweight Mount is unique. The rigid design has no joint between the scope and rifle. The Talley Lightweight unitized design eliminates the possibility of an "out of alignment" interface or "loose connection" between the ring and base of traditional two-piece design. CNC machined from 7000 series aluminum, known for its strength and durability.Notes:Ring Height (from top of receiver to bottom of scope tube):Low: Front .400", Rear .510"Medium: Front .500", Rear .610"High: Front .600", Rear .710"Includes attachment screws and allen wrenchMay require drilling and tapping of firearm receiver for installation