The Johnson Heavy-Duty I-Beam Aluminum Level comes equipped with oversized 1/2 in. Not only are the vials themselves easy to read, but the heavy-duty aluminum level has more vials than competitive models in 48 in. and longer lengths, meaning the vials are always within eyeshot, even at awkward angles. Finally, this aluminum level also features Johnson's SurroundView technology to maximize visibility, and top read windows allow the user to stand over the work to view the vials.