When the ladder is opened, the joints are placed. If you hear the "click", it means that the ladder is fixed, so it can be used safely.
The ladder is once every 45 degrees. This is also a warning function. It needs a switch at the joints.
Excessive drinkers, those who like to doze (fatigue), barefoot and slippers are advised not to go upstairs for a long time.
When the ladder is folded, do not hold the ladder, because the 0 gap coincides. You should hold the pedal with clearance.
Please fold the ladder when it is not used.