The Omega 1220 watch movement, produced from 1972 to 1974, features a special regulator accessible through the opened battery cabinet. The stem can be released by sliding a mechanism. This non-self-starting movement incorporates a hack mechanism that halts the balance in a position enabling reliable starting when the crown is pushed in. Its functions include an electronically controlled balance motor, sweep second hand, day indicator, quickset date achieved by repeated crown pushing, electronic nature, shock protection, and a calendar with quickset capabilities.