The Protectors (1964)
The Protectors (1964) was a British crime series produced by ABC and is not to be confused with the later and much better-known ITC series. It ran for only one season - like so many British series of the 60s and 70s it was shipwrecked by industrial disputes. The firm of Souter and Shoesmith refer to themselves as the SIS (Specialists in Security). The full series is here.British TV Catalog