DescriptionLuxylite 30-60-90 degrees 6" drawing/drafting triangle no. 1851-6 made by Keuffel & Esser, New York and Hoboken, no date, circa 1950-1960. Clear plastic with square edge profile; recesses - "finger lifts" - in center cutout. It is marked with company logo, name, Luxylite trademark and product number. K&E had their main office and factories in Hoboken up to December 1968.