Details
A Roplex calculator,
in square perspex case with two fixed scales and two revolving scales and cursor operated by knurled wheels at top corners, in slipcase -- 5.3/8in. (13cm.) wide, French
in square perspex case with two fixed scales and two revolving scales and cursor operated by knurled wheels at top corners, in slipcase -- 5.3/8in. (13cm.) wide, French