It seems to me that having multiple vials in the same orientation is redundant, but many levels seems to include this feature. What am I missing? There has to be some reason.
Why do Contractor Levels have two vials with the same orientation
contractorsleveltools
Best Answer
It's useful when using the level in the vertical direction (to e.g., check studs for plumb-ness) so that the bubble is at or near eye level no matter which end is up.