This device prevents unauthorized people from climbing on ladders leading to dangerous or controled areas. The vertical panels with two hinges are supplied either in galvanized steel or in aluminium. They can fit every kind of existing or new ladder without any modification. They can be locked either with a padlock or a security lock. They match the requirements of the NF E 85-012 and NF EN ISO 14122-4 standards  as far as their dimensions and mechanical strengh are concerned.