?Adjustable?0-270° angle range, 30-49 Inches measuring range.
?Accurate Measurement?After snapping the left and right ends of this ruler firmly in the middle of the stairs, it will accurately measure the width of the stairs.
?High Stability?The 4 knobs can firmly lock the ruler in the right position, so it wont move during the measurement.
?Easy to Install?If you twist the knob clockwise, it will be tight. on the contrary, it will become loose. by turning these knobs, you can easily remove and install this ruler.
?Durable?This ruler is made of high-quality birch wood, which is not only hard but also anti-corrosive and environment-friendly.