CVLIFE Scope Bubble Level 1in 30mm Scope Level Anti Cant 30mm ONE anti-cant two size: 1in and 30mm This scope bubble level can be used for two scope tubes in tow size ADJUSTABLE liquid tube of the scope bubble level, set a position as you like GREEN liquid of the scope bubble level, notice the level bubble to ensure the scope in horizontal Aluminum alloy material for the scope level, LIGHT but DURABLE