Designed for installing double-flight staircases in residential buildings with brick walls and floor heights of 2.8 m or 3.0 m.

They are used to construct strip foundations for cellars, utility rooms, unheated buildings, basements, and ground-floor spaces. They are designed to span openings in brick walls. For lintels with a load of less than 800 kgf/m, no floor support is provided.