Topcon RL-H5B Horizontal Self-Leveling Rotating LaserTopcon RL H5B Horizontal Self Leveling Rotating Laser MULTI PURPOSE LASER: Grading, excavating and general construction projects are perfect applications for the RL H5B. With the IP66 rating, the RL H5B is "job site tough" and can withstand dust, a sudden shower and even torrential rainfall. EASY TO USE: With electronic self leveling, you press the power button and go right to work in seconds. If the RL H5B gets disturbed on the job it relevels itself