Geissele Suppressor Alignment Gage 9mm. It is important to understand that the length of the suppressor is usually much longer than the length of the barrel / muzzle device / suppressor interface geometry. A small deviation at the mounting interface means a much larger deviation of the suppressor exit hole. The deviations from nominal can also be additive which compounds suppressor misalignment. Specifications for Geissele Suppressor Alignment Gage: Manufacturer: Geissele Width: 1 in Condition: New Package Contents: Geissele Suppressor Alignment Gage Geissele 10-451-F: Suppressor Alignment Gage 9mm