Draper expert 250mm plumb site dual view torpedo level with magnetic base draper expert 69554 b i expert quality i b magnetic v groove level with front viewing plumb site 174 dual view 153 vial the v groove is especially useful in levelling pipework three vials horizontal 45 176 and vertical with plumb site 174 dual view 153 window accuracy 1 75mm per 1m 0 1 176 in standard position manufactured for draper tools by kapro display packed draper expert 69554 250mm