Calibre ETA 2671 Automatic | 17 jewels | Diameter 

In 1972 Nepro Memotron was introduced @ Baselworld as being world's first mechanical watch with an electronic alarm. The calibre ETA 2671 (used in ladies watches) automatic movement was used in order to make space for the world's smallest acoustic generator called the MicroBuzzer 500.

Nepro Elevox & Memotron II

The other model Nepro introduced in 1972 was the Elevox. A mechanical  watch (Cal. FHF 69) with an electronic alarm which resonates through the crystal of the watch. One year later a new Memotron was issued containing a fully battery operated dive-balance movement by Porta (Cal. 651) and an electronic buzzer. 

Swiss patented

At the time Nepro introduced their Memotron and Elevox, the Swiss Made signature wasn't granted yet so both dial and case back are signed Swiss patented.

Nepro Minisonic Alarm Clock (1970)

Look at this miniturized alarm clock from Nepro, called the Minisonic. At that time world's smallest mechanical clock with battery driven transistorized alarm. Measures only 3 by 2 by 2 cm. Nepro targeted this product at housewives as the advertisement shows. Truly designed for pocket or handbag. It came with a discreet and practical leather case. On the dial it says swiss pat. rotocontact which refers to the clock with electrical radio-contact. This technique was originally issued by Nepro in 1961.

The Nepro Minisonic is powered by the hand wound mechanical FHF 69 movement.