Features: Allows the shooter- to obtain proper eye relief. Aircraft Aluminum Alloy. Universally- Use for 30mm/25.4mm. Eliminating the need to span from the receiver to the hand guard. The bubble level which can be flipped- to the side also allows you to have an additional indicator to achieve much higher accuracy. Angle Degree/Cosine- Indicator (ADI-/ACI-) takes the guesswork out of uphill- and downhill- shots.The red needle moves with your rifle- and displays a number that indicates the percent your rifle- is off level. Specifications: Material: aluminum alloy Package Includes: 1x Angle Cosine- note: Please allow 1-3cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item.