Vortex LBL-30 Lo Pro 30mm Bubblevel
This slim, low-profile design allows the Bubblevel to be mounted on most scopes without removing the scope from the rifle. It is easily visible without losing the sight picture.
Features:
Outside Diameter (inches): 2.2 - 2.4 inches
Outside Diameter (mm): 55 - 61 mm
Weight: 0.4 oz.