The Vortex 30mm Bubble Level is a precision accessory designed to help shooters eliminate one of the most common causes of missed shots at distance-rifle cant. Engineered to mount directly to 30mm riflescope tubes, this bubble level provides a quick, visual reference to ensure your rifle is perfectly level before every shot. Lightweight, durable, and unobtrusive, it's an essential upgrade for long-range shooters, precision rifle competitors, and hunters who demand consistency and accuracy. Specifications: Manufacturer: Vortex Optics Product Type: Riflescope Bubble Level Scope Compatibility: 30mm tubes Weight: 1.6 oz Outside Diameter: 2.2-2.4 inches 55-61 mm