Precision Machined From Aircraft-grade  Aluminum Alloy with Anodized Black Matte  Finish. 

Fully Adjustable to  Fit on Any Picatinny Rail.

Tight Tolerance Control with Anti-rotation  Feature to Guarantee Most Positive and  Repeatable Zero and Re-zero Capability.
Overall Low Profile Crocodile Design and  Light Weight Machine Cut for Optimal  Tactical Applications.

Specifications:

Material: Aluminum
Ring Diameter: 25.4mm/30mm adjustable

Weaver Size: 20mm

Height: 62mm