Draper expert 300mm plumb site dual view box section level draper expert 69543 expert quality with front viewing plumb site174 dual view153 vial aluminium box section extrusion electrostatically powder coated and baked with polyester acrylic paint all have a milled base except 1800mm the 300mm and 600mm sizes have one horizontal vial and one plumb site174 dual view153 vial the 900mm and 1200mm sizes have one horizontal one plumb and one plumb site174 dual view153 via