The interior and exterior rotary laser level is accurate to 1/4 inches at 100 feet. It is constructed to withstand rugged jobsite conditions with a durable rotary cage that helps protect the head if dropped. An innovative configuration of multiple thin struts maintains the unit's strength while eliminating blind spots. The unit is self-leveling in horizontal mode, and in vertical mode, arrow buttons used for manual leveling are more intuitive than traditional knobs. Sharp and bright, the beam approx.