This object is not on display at the National Air and Space Museum, it is either on loan or in storage.
Transferred from the Department of Commerce, Bureau of Standards.
Country of Origin: Germany
3-D Test: 5.5 x 10.5cm (2 3/16 x 4 1/8 in.)
Physical Description:105mm diameter, 55mm deep; red and black scales; chrome casing.
Inventory number: A19570029000