The Interior and Exterior Rotary Laser Level are accurate to 1/4 inches at 100 feet. It is constructed to withstand rugged job site 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 can be seen up to 100 feet indoors, and can be recognized at up to a 1200-foot diameter outdoors with the included detector. The laser also offers a weather-resistant housing for durable and accurate performance.