This boarding ladder is a substruction so the ladder is invisible when it is retracted. It is made out of stainless steel(AISI316) and it is naturally resistant against water and ultrviolet radiation. measurement: total length:114cm retracted length:44cm width:30cm width of the steps:40mm 2 drillings to stick the ladder base plate length: 15 cm contactplate:21x5cm(lengthxwidth)