Drink mixer. Thick, cylindrical glass container, bottom embossed (backwards): "ROBERTS LIGHTNING MIXER", and has sticker with "425" handwritten on it. Mixing apparatus is comprised of flat metal circle, punctured with circular openings, with four curved metal protrusions, attached to a twisted metal shaft, which passes through flat hole in top of domed metal lid. White plastic knob for handle at top of twisted metal shaft. Pulling handle creates mixing action. Metal cap sits over top of glass container. Top of lid is stamped: "ROBERTS LIGHTNING MIXER/PAT'D 1913/NATIONAL CO. BOSTON, MASS."
Patent number US 1068450 A, July 29, 1913, Henry P. Roberts, Boston, Massachusetts, assignor to Dorsey Manufacturing Company, Boston, Massachusetts, for "Beater and mixer".
Maker is National Company, Boston, Massachusetts.