More than just an anti-cant device, this ScopLevel Anti-Cant Device is
also a great tool to use to align your rifle scope to the bore. The level
is easily visible above the vertical crosshair with your sighting eye to
help you aim and verify that the vertical crosshair is plumb.
This particular ScopLevel Anti-Cant Device comes in a 30mm diameter for
use with rifle scopes with a 30mm objective tube. With this simple tool,
it is easier than ever to align your rifle scope to keep cant from
interfering with your aim.