Strand Memory.

3v (2x AA batteries).

Display is 8 digits, green vacuum fluorescent.

4 functions, %, memory, square root.

78 x 136 x 26 mm. (3" x 5.4" x 1").

Made in Japan.

The label on the rear says "Supplied exclusively to W.H. Smith by Decimo".
W.H. Smith is a British chain of newsagent, book, stationery, and music stores.

The circuit board with NEC uPD278C integrated circuit and vacuum fluorescent display in a single tube.

Decimo models