With this Kreator 360° cross-line laser, you can project both a vertical laser line and a 360° laser line from a single point. This makes it perfect for tasks such as wallpapering or tiling the lower half of a room. By projecting the vertical laser line and the 360° laser line together, you create a cross line. The device features a locking function, ensuring that your lines remain vertical even after a directional change. The laser will start blinking if it is no longer horizontal. The KRT706320 self-levels within six seconds with an accuracy of 0.5 mm/meter. For the highest precision, you can also mount the laser on a tripod. 2 AA batteries are included. Battery required: Yes. Required batteries (quantity): 4. Batteries included (quantity): 4.