Transferred from the Department of Commerce, Bureau of Standards.
Country of Origin: United States of America
3-D Test: 7.6 x 16.5 x 17.8cm, 1.4kg (3 x 6 1/2 x 7 in., 3lb.)
Metal and glass.
Black Metal rectangular case with glass face cover. Range 20,000ft; developed by R.D. Kelly; 1929; experimental; vertical.