YouTube

 

   

TI 551 10Model: TI-551-10 Code: Ok
Battery:
  309
WCase: black plastic WBand: matching bracelet Face: silver frame 
Manual: Yes  Box: No  Lamp: Tritium
Year: 1977 Price: $ 19.90
Function: The watch has five functions- hours, minutes, seconds, month and date
Info: 
the same model in brown TI-551-02