Alvin smoked acrylic professional drafting triangle. Quality INKING EDGE drafting triangle is constructed of molded 0.10" thick polystyrene plastic and features a transparent non-glare smoke tint for easy visibility. Edges are double-beveled with handy fingerlifts for quick placement and removal. Supplied in poly bag with hanging hole. Alvin 30/60/90 4" drafting triangles are made in the USA.