Johnson's 40-6639 Self-Leveling Line Laser is the best solution when you need to mark a level plane across a wall. This laser can be used indoors and outdoors. When you are out of leveling range, visual and audible alarms will sound. In manual mode, you can tilt the unit to extreme angles and still have an accurate measurement.
This item is and is only listed as new/very good because the casing is slightly damaged with a cut. (SEE PHOTOS)