When mounting optics, precision is the name of the game and there's one piece of gear that will be critical to your success: the Weaver Modular Level System. These tools are a simple, yet effective, way to guarantee a scope's crosshairs are level with the receiver. Accuracy here will help you maximize your optics investment out there. Product Specifications Manufacturer: Weaver Optics Model: Various Caliber: Various Capacity: N/A