Sinclair Cambridge Electronic Calculator Kit

Brand: Sinclair Radionics Ltd.
Model: Cambridge Electronic Calculator Kit
Made in: United Kingdom
First year of production: 1973
Price: £27.45 (£32.95 assembled)

Dimensions: 50 × 112 × 18 mm
Weight: 57 g

Has [C/CE] (one press clears last entry and two presses clears everything) and [K] (constant) keys.
Runs on 4 x AAA batteries (6v).
Main IC is a General Instruments Microelectronics GIMT-CZ550.