External Bubble Level Assembly designed to attach forward on the scope mount body or ring. Perfect solution for shooters who are unable to focus on the built-in level in the standard ISMS series or who has a model without a built-in level. The angle of the assembly can be adjusted using two set screws. Includes screws. Width: 29.5 mm/1.16” Height: 41.6 mm/1.64” Length: 32.1 mm/1.25” Weight: 20 g/0.7 oz