Features:
OOTDTY  
Fit for 21mm weaver-picatinny mount dovetail mount. With hex-key,accurate made.
Small size allows for convenient storage and transport.
Eliminate canting and improve long-range accuracy with these on scope mounted spirit levels.
High quality materials, exquisite technology, fine workmanship, better impact / more durable.
These bolts are mounted on the horizontal-surface of the oscilloscope installation to eliminate tilt and misalignment.

Specifications:
Material:Aluminum Alloy
Size:As Picture Shown
Type: Cylindrical level(Without wrench)
20mm
Color: black shells + green-liquid

Package Includes:
1x Bubble Level

Note:
1.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order.
2.Due to the difference between different monitors, the picture may not reflect the actual color of the item.
Thanks for your understandings.