Makita SK104Z Self-Leveling Horizontal/Vertical Cross-Line Laser Line visibility range up to 50' depending on ambient light in working environment Accuracy - horizontal line (+/- 1/8" at 30'); vertical line (+/- 3/32" at 30') Fast self-leveling time; stability is achieved in 3 seconds for increased productivity Self-leveling is correctable up to 4 of slope allowing operation on uneven surfaces Bright 635 nm class II laser for best-in-class visibility in moderate ambient light environment. Maximum radiant output power for classification is 0.95 mW