The Stair Step Scribe saves time and money by taking the guesswork out of uneven stair treads. Just line up the fully adjustable arms against a stair's edges for the perfect measurement to transfer to any flooring. This new and improved version includes comfort-grip knobs and opens more smoothly. Simple three-step process to professional looking stair treads Efficient - get perfect stair tread faster Economical - stop wasting material Measures stairs 28.5-in to 48-in wide New comfort-grip knobs and slider system improve ease of use Made in the USA