For the serious builder or contractor who requires greater accuracy. Designed with a heavy-duty dome shaped head that holds a double ball bearing center, giving the user 5-minute readouts. Has a 1 vertical arc and two leveling vials, 3-1/2" x 8 thread. Accuracy: 1/8" @ 100'. Working range 250?. Non-strip focus knob, Built-in sunshade, Large coated achromatic lens, Rubber eyepiece cap, Brass leveling screws, 4-1/2? short focus. Berger Instruments - proudly made in the USA since 1871. Tools and Hardware