Details...

• Character: Sherlock Holmes
• Actor: Benedict Cumberbatch
• Show: Sherlock
• Episode: 2x01 - "A Scandal in Belgravia"
• Brand Product : Shodan (初段) Judo Diploma Certificate First Dan
• Buy:

  A vintage Judo certificate for Jeffrey de Beshu from 1965 (source) is often assumed to be the one used in Sherlock, however the image was only used for comparison purposes on identification websites and is not the one used on screen.

• Credit: Sherlockology, Wear Sherlock, Ask Meta Filter