The U structure or runner forms the horizontal component of the steel frame structure in drywall. This structure is implemented on the floor and ceiling and acts as a conductor for teachers. In addition, this structure is also used in the horizontal parts of the openings.

The cross-section of this profile is U-shaped and it is produced according to DIN and EN standards with a width of 36 and a thickness of 0.5 and 0.6 mm.