Atibal Extended Scope Bubble Level 30mm Anodize Black. Fits all 30mm scope tubes. Includes 1in reducing sleeves. For best results level the bubble on your scope while the arm is extended. Specifications for Atibal Extended Scope Bubble Level: Manufacturer: Atibal Color: Black Finish: Anodized Fabric/Material: 6061-T6 Aircraft Grade Aluminum Fit: Scope Tubes Tube Diameter: 30 mm Features of Atibal Extended Scope Bubble Level Lifetime Warranty One Piece Construction Up to 40000 hours of battery life RMR Compatible Mounting Pattern 4 hour auto shut-off Precise windage/elevation adjustments Package Contents: Atibal Extended Scope Bubble Level Atibal AT-ESBL: Extended Scope Bubble Level 30mm Anodize Black