FHR Head Restraints provide the necessary restraint at the top of masonry walls.The smaller angle is fitted below the larger angle to form an "F" profile over the head of the blockwork taking care to line up the holes in both the smaller and larger profile.The two holes in the larger profile are set for 100mm and 140mm thicknesses of masonry.The two profiles are then bolted to the underside of the structure using the appropriate fixing.