Professional wood ladder , ideal for electricians, fitters, drywall installers in particular. Spruce wood stiles and beech wood rungs, made of first quality wood selected. - Excellent electrical insulation - Distance between the rungs 250 mm. - Lateral spruce uprights mm.70x24 with rounded corners - Beech wood rungs section 21 x 41 mm milled anti slip - Joint of the rungs with double tenon glued - Steel tie rods and anti-opening security chain - Guiding rails at the base of supports - Anti-slip rubber feet under request - Double transparent lacquered wood - Manual of use and maintenance with a declaration of conformity with European standard EN 131