The Spectra Precision LL400 Laser Level for concrete and site-preparation applications features one-button operation for basic leveling and provides accurate, long-range measurements — even for machine-control applications. Features include fast set-up, minimal training time and automatic self-leveling. A rugged design and patented lighthouse seal protect the rotor head and glass and provide drop and weather protection. The single-axis slope mode provides grade matching with self-leveling cross axis. Four customizable kits with choice of receivers are available.