Includes: Level bubble scope mount Materials: 6061 Aircraft Grade Aluminum Scope Compatibility: 1inch, 30mm, or 34mm Scope Tubes Weight: 1 oz Finish: Hard Anodized Black Warranty: Lifetime Line your shots up consistently each and every time! The Monstrum Rifle Scope Level Bubble is a tool built to check for proper vertical alignment of your rifle. Imperfect vertical alignment of your scope when shooting introduces scope cant error - horizontal drift of your shots due to cant. In uncontrolled shooting environments, it is common for the naked eye to misjudge vertical alignment by 2-3 degrees. A slight cant of 3 degrees can result in your shot being off by three inches at 400 yards and is compounded further at longer distances. An anti-cant level bubble corrects for this issue, allowing you to quickly check for proper alignment of your rifle before each shot. The level bubble attaches to your rifle scope via the integrated ring mount. Crafted from lightweight 6061 grade aluminum. All Monstrum optics and accessory products come with a lifetime guarantee.