The tuning fork watch of the Japan-Electric-Clock Co. of Tokyo, Japan (Jeco Co.Ltd). (Patent 33.310, 38.338, 38.339 and 59.331 Japan 1963). The Jeco has a curious magnetic escapement and must be started by hand. It is unknown whether commercial production ever took place. Jeco also manufactured tuning fork clocks by themselves under licence of Bulova.
Tuning Fork Watches · No. 4
4. Jeco
Jeco Japan made tuning fork wristwatches under licence of Bulova.