DescriptionTwo 45 degree Luxylite drawing/drafting triangles sold by Keuffel & Esser, New York and Hoboken, no date, circa 1965-1975. One each: no. 57 0292 8, 8"; no. 57 0292 4, 4". Clear plastic with recessed edge ("finger lifts"; also useful when inking.) Besides company name, Luxylite trademark and product number, they are marked "Denmark." These items may be earlier in the 1960s than 1965 and possibly later than 1975. K&E had their main office and factory in Hoboken up to December 1968.