PLS90 SYSTEM PRECISE 90 DEGREE LAYOUT Designed to tackle one of the most challenging layout tasks on the job PRECISE 90 DEGREE LAYOUT LINES. Visible and pulsed "for use with PLS-SLD Detector (not included)" reference lines for interior and exterior layout of square on the jobsite. Square on slope. Square on grade. Fully self leveling, visible indoors to +/ - 100 feet. Outdoor range is 250 feet with PLS-SLD Detector (not included). Accurate to 1/8" @ 100 ". Great for clear bright square lines indoors for floor tile work. Alignment to second layout point is "dialed in" with a built in adjustment knob.