Dating to the mid 1960s, this is a good working example of an Otis King's Model 'K' Type C cylindrical sliderule calculator, with black on white scales numbered 414 and 423.

Stamped 'Made in England' around the serial No. X3112 on the base, together with Patent No. 183723, it is in good condition, retaining all of its chrome plating, although there is some sporadic blistering of the black paint on the main barrel in places (see photos), the scales are clean and scuff free.

It is in good working order and comes in its original cardboard box, along with the original eight page instruction booklet and a later copy of a blue marketing leaflet.