Gun and Run (Deca-01) Red Dot Variable Magnifier 3X - 10X for Eotech Only 2.7-9.5 X 40 Magnifier for Laser Collimated sights : Magnifier for Eotech Magnification 2.7X - 9.5X Tube Diameter: 30mm Mounting Tube Length: 7.5" Eye Relief: 3.1 Inches Water Proof / Shock Proof / Lightwight / Compact