By The London Name Plate Mfg. Co. Ltd. Stores ref. 6B/166. 1940 date code. Circular white metal instrument. Has rotating discs for setting the ground pressure, temperature, indicated height and airspeed. For use with ICAN calibrated altimeters. Used by Navigators when plotting routes etc. One of the small metal 'feet' is missing (see photo), otherwise in good '+' used condition. Well marked. Stock code M17753.