It's a helper for building drywall ceilings without help of another person. Also you can perfectly adjust the height using a laser. Using 2 or 3 of this helpers you can place the profile on the helper and have your hands free for screwing. The notch on the side of the tool is the mark for the laser. Use a rotary laser and adjust the heigt, that the laserline matches the notch. Yoe will get a perfect alligned ceiling.

It is an easy print without any special needs