High Accuracy Angle Cosine Indicator Kit and Bubble Level Fit 1 inch 30mm Tube Rifle Scope Mounts Light Weight Made of AluminumFeatures:1. Red Neddle: The red needle moves with your rifle and displays a number that indicates the percent your rifle is off level.2. Indicate Percent: Multiply the indicated percent by the target distance to easily calculate the adjusted distance for gravity.3. Bubble Leve: The bubble level which can be flipped to the side also allows you to have an additional indicator to achieve much higher accuracy.Description: This is the rifle Scope ring which helps you to adjust. With easy operation helps you with your gun using. Specifications:Color: Black Material: Aluminum Alloy Package Included:1 x Rifle Scope Ring