The GLL 55 and GLL 100 G line lasers feature VisMax electronic controls that monitor the temperature of the laser diode to maintain visibility while preventing damage from overheating. The GLL 55 is a red-line laser that is visible up to 50 ft, and the GLL 100 G is a green-line laser that is visible up to 100 ft. Both lasers emit horizontal and vertical lines and can self-level when set on uneven sufaces.