British Thornton was the premier maker of slide rules in the UK. Their earlier celluloid and wood rules were sold under the PIC brand but this one is all plastic.

The rules has 12 scales: LL1, LL2, LL3, A, D, S, ST, and T on the stock; B, CI, K, C on the slide.

The rules show slight signs of use but all in in very good condition.

A hard plastic case is provided.

A photo-copy of the original documentation will be provided.