Warne USL30 Universal Scope Level 30mm Tube Diameter Universal Aluminum BlackWarnes Skyline Universal Scope Level allows shooters to easily keep the reticle level without changing their position on the rifle. Whether moving through thick brush or storing your rifle in a case or scabbard, our patent pending design allows the shooter to deploy or stow the indicator with a simple push or pull. Easily attaches to your scope tube for right or left hand configurations.