The Porta Uhrenfabrik Wehner KG (PUW) in Pforzheim produced two electric watches with the coil on the balance and mechanical contacts, all with three magnets and a frequency of 4 Hz.
| 1960 | Porta starts to sell the Lip R 27 under the name Porta-Lip. |
| 1969 | The Porta Elechron caliber PUW 1000 without date, the Porta 1001 with date and the 1002 with day and date are released. The watch is also sold by Croton, Gruen and Feuver. |
| 1972 | The Porta Ladychron caliber PUW 3000. Also sold by Pallas-Ormo, Elgin, Fleurier, Gruen, Helbros, Helvetia, Invicta, Solvil & Titus, Sandoz and Waltham. |
| 1991 | Porta is taken over by the Swiss holding SMH. |
