Within this episode Walter replaces both his calculator watch and 2004 Pontiac Aztec, which were integral parts of his representation as a mild-mannered suburban school teacher. The respectively sleeker models they are replaced with, and the recovery of his signature pork pie hat, symbolize his final consumption by the Heisenberg persona.
This episode was Anna Gunn's submission for the Best Supporting Actress in a Drama Series category in the 2013 Emmy Awards- her second nomination for the show and first win.
First time Walter sits in the boss chair.
The TAG Heuer Swiss chronograph watch that Jesse gives Walt for his birthday is the reissued "Monaco" model popularized by Steve McQueen in Le Mans (1971).
In the end of the episode, Skyler uses a mug for an ashtray. On the mug is printed the number 51, the same as the title of the episode which presumably relates to Walter's 51st birthday.