Specification:Product name:Right angle ground wire instrumentHorizontal accuracy: 0.5mmAngle deviation: 0.5mm/mWorking time: 3-5 hoursLaser wavelength: 520nm-635nmIndoor light length: 15mBattery: 3 AA batteries (note: the product does not have batteries) Features:1. Shoot a laser line on the surface of the object, the line can be at any angle. Single line and double line operation can be 90 degree angle2. It is suitable for carpentry, stair starter, shelf, molding, tile laying or any other work that requires precise alignment.3. Double bubble level is used for plane or straight alignment accurately, and the recyclable I-shaped needle keeps it still when working in a straight line.4. ON/OFFswitch device.5. This is a laser square designed specifically for craftsmen. It maintains the characteristics of the original square, while outputting two extended 90 right-angle laser chalk lines, which can significantly extend the length of the square. The marking angle can also be changed according to the measuring angle scale, which saves the time of measuring angle and marking. It is an effective tool for angle stakeout.Packing list:Right angle ground wire instrument and 2 suction cups