made of galvanized steel,ladder hinges easy to install，tie rod installed at ladder side top hinge size is divided into different sizes; Small size is suitable for the total width of the ladder 12cm-13cm, Large size is suitable for the total width of the ladder 15cm-16cm（as the picture shows；Measuring the top of the ladder） attic ladder hinges provide as safe and stable ladder spreader brace adds stability and prevents damage apply to home ladder/photography folding ladder/herringbone ladder etc